Characters getting a Promotion to Parent in fan works.
Crossovers
- In Harry Tano, Ahsoka (who's still an older teenager at that point) comes across a four-year-old Harry by accident after being sent to Earth by a mysterious device. She gets him away from the Dursley house and quickly becomes his caretaker, to the point that Lily's ghost declares Ahsoka Harry's new mother, and Harry begins calling her "mum".
- The Secret Return of Alex Mack: When Alex rescues eight-year-old Shar from The Shop, Alex's parents agree to let Shar stay with them, since Alex is one of the few people she trusts, but they make Alex responsible for a lot of her care — getting her up and ready, taking her to and from school, making sure she does chores and homework. Alex's mother eventually encourages Alex to slow down a bit; she doesn't have to fully take over as a parent. But she still has, and feels, a lot of responsibility for her new little sister. Which means that when Shar makes a Heroic Sacrifice to end a Grey Goo threat, Alex's world is shattered.
- Kristoph parented Klavier for a while after their parents died in a car accident in Dirty Sympathy. It obviously didn't end well since Klavier immediately left home when he was 15 and they both hate each other by the time the fic takes place.
- The Great Ace Detective: Klint van Ziek had raised his younger brother Barok from a young age after their parents' death. It's one of the reasons why Barok holds him to high esteem, and why he fears that because he held Klint upon such a pedestal that the latter won't confine Barok if something is troubling him.
- Iris Hawthorne: Ace Attorney: Iris becomes the guardian for her half-sister Pearl after their mother Morgan was arrested for her part in killing Diego and framing Maya.
- A Meaningful Sacrifice: Joon-yeong to his younger sister, Soo-wi, after the deaths of their parents. It's the source of much stress for him as he's still a teenager, until eventually, he has to get help from the few trusted adults in his life to take care of her.
- Us, Withering Under The Sun: Woo-jin and Ha-ri's parents are extremely neglectful of their son, as both of their parents favored their daughter with their mother being outright emotionally abusive to him while their father was more oblivious to the pain his son was going through. As a result, despite only being a year older than him, Ha-ri is left being the only one there to act motherly to Woo-jin, especially when he experiences vicious bullying.
- Basically the core of the story in Family
, following Yakko Warner as he tries to raise his siblings before and after their neglectful parents either die from a drug overdose (Mom) or abandon them (Dad).
- All Assorted Animorphs AUs: In "What if Rachel's mom was a controller?", Naomi has been distant from her daughters since she was infested, and she was already divorced, so Rachel has to take care of her sisters single-handedly.
- Forging a Better Future:
- Sara eventually realizes that Laurel is the only real parent she's ever had since she's the one who tried to teach Sara right from wrong instead of spoiling her like Quentin and Dinah did. While it does help them reconcile their relationship further, this revelation nonetheless hits them both hard, especially Sara.
- Just like in Arrow: Rebirth, Oliver takes permanent guardianship of Thea upon Malcolm's exposure as the Dark Archer. The only difference is that Tommy gave up guardianship willingly, recognizing that as the city pariah, he can't be an effective guardian for Thea right now. That being said, he still shares the responsibility of actually raising Thea with Oliver.
- Lois apparently had to raise her younger sister as well. Like Sara, Lucy resented her for it. Unlike Sara and Laurel, they haven't reconciled yet.
- To Hell and Back: After the destruction of Krypton and landing on Lian Yu, Kal-El was initially raised by a makeshift family, with Slade and Shado as the "parents". After Shado's death and Slade's disappearance/presumed death, however, he was then raised by his "siblings", Kara, Barry, and Oliver, with the...questionable help of the League of Assassins.
- A consequence of Kara and Kal travelling in the same ship is that the former becomes her cousin's legal guardian.
- In most fan fictions, Mungojerrie is often the protective one (Rumpleteazer often written as the younger sibling) and it is a fan WMG that Macavity killed their parents.
- An adult example in To live again: Alex and Annie were in an aunt/niece-like relationship in Annie's childhood and when they're reunited they just think of it as a chance to friendship... Then somewhere along the way Alex becomes Annie's Mama Bear and Annie decides that Alex is the best mom she could ask for. And you don't mess with Annie's mom. Ever.
- In the Dusk to Dawn fan novel series, this is deconstructed in Catwoman's backstory. Selina had to be a mother figure for her sister Maggie after their parents died, and was way too wild and irresponsible to be up to the task. Realizing this, Selina left her sister behind in an orphanage where she believed Maggie could have a normal life. She didn't. The Corrupt Church funding the orphanage took Maggie shortly after, and raised/brainwashed her into their borderline superhuman warrior.
- A Force of Four (Power Girl): Superman tried to serve as Kara's father upon his cousin's arrival, but she couldn't regard him as her own father.
- one day at a time: In the backstory, an adult Jason Todd was forced to raise his younger sister Helena Wayne after the death of her mother Selina Kyle, with help from his sister Cassandra Cain. This is due to Helena's father Bruce Wayne (Jason's adoptive father) having been dead since before she was even born, with all of Jason's brothers following him five to seven years later. Years later, he also had to raise the orphaned Terry and Matthew McGinnis after learning they were also Bruce's biological sons. As Jason was a fully-grown adult when all this happened (being already thirty years old when Helena landed on his doorstep), they're practically his children and he treats them as such. In the first chapter, Helena even expresses disgust at the idea of Jason being her brother, as he's firmly her father in her eyes.
- Retrograde Motion (Batman): Because of all the baggage Bruce has with the older Jason, Dick ends up becoming the primary father figure of the younger Jason. Barbara even uses this as a basis for Jason's cover story after he starts going out in public, by making Jason Dick's (probable) lovechild with Artemis. When it turns out the transformation is irreversible, the promotion becomes permanent, with Bruce electing to become Jason's 'grandpa' instead.
- In Supergirl (2015) fic Survivors, Kal and Kara's parents die on Krypton and Kara becomes her baby cousin’s mother de facto upon crash-landing on Earth.The mention of her mother almost took her back, but she shook her head. There was no time. Kara was a practical girl now. She had to be. No more playing, no more crafts, no more classes... no more anything. She was a mother for all intents and purposes. A 13 year old homeless mother on a strange world with no food.
- Heartbroken that her parents gave her up so easily and her developing bond with her Tío, Mirabel in The Two Seers is quick to refer to Bruno as her dad.
- A bit of an odd example in The New Retcons, in that no parent actually died, but when Elly started to go insane, she denied that April was ever her daughter and threw her out. Since April was still a minor, this could be applied to her older brother Michael, who took her into his family. A lot more plausible when John gives up on convincing Elly that April's their daughter, effectively disowning her.
- Later, they're introduced to their half-sister, Claire, who winds up becoming more of a mother figure to April than Elly ever was. At one point, April remarks that with their 22-year age difference, Claire actually could have been her mother, since Claire was the result of a Teen Pregnancy while April came very late in life.
- Cody in Five Nights At Freddy's: Lost Souls has become a parental figure to his little sister Bridget, as unlike their mother, their father is often out of town, and also unlike their mother, their father is still alive.
Game of Thrones/A Song of Ice and Fire
- A common occurrence in A Song of Ice and Fire fanfics where the Targaryens win in Robert's Rebellion and Prince Rhaegar becomes king. In addition to his own young children, he also has to raise his siblings; he's 25 at the end of the war, but his brother Viserys is 8 and his sister Daenerys is a newborn. Granted, the situation is a lot easier for him to deal with since he's a king.
- Abraxas (Hrodvitnon): In Chapter 10, San reveals that in Ghidorah's backstory, long before the trio became the Omnicidal Maniac we all know Ghidorah as, Ichi/Eldest Brother had to rear the other two brothers himself in the absence of any parental figure since they hatched.
- In Daisy Dursley Harry's aunt and uncle announce that their infant daughter is a "freak" after she exhibits accidental magic and make Harry responsible for her care. After his cousin Dudley worries that he might be classed as a freak someday too, the two boys make a blood oath that they and Daisy will always be a family of their own.
- In the Dangerverse series, Hermione's parents are killed by Death Eaters when she's still a baby, and she's raised by her big sister, Danger.
- In The Little Child to Lead Him Harry decides to care for his infant cousin after his aunt dies giving birth to her and his uncle blames it on the baby.
- Percy Take the Wheel is a Harry Potter fanfic where an accident kills Molly and puts Arthur in a coma, leaving Percy to raise the younger Weasleys. (Bill and Charlie are supporting the family financially, but this means staying at their jobs overseas.)
- Averted in When Paths Cross where the older child left the then-fifteen-year-old main character in an orphanage after the death of their parents rather than even try to take care of her.
- In The Hunger Games Prequel Collection, Terra acts as a parental figure to her younger sister, Iry. The girls' mother died when Iry was born and their father was killed in a factory accident six months before the Thirty-sixth Hunger Games.
- In Painted Blind, it's mentioned that Stormer and Craig's father ran off when they were kids. Their mother was a Struggling Single Mother who worked two jobs, leaving Craig practically as his sister's second parent. This explains his overprotective nature towards Stormer.
- This happens with Satsuki and Nui (mostly the former) in Cellar Secrets. In light of Rei's suicide, their mother being committed and living in the care of a mental hospital before later on dying of a terminal illness, and the fact that their father died years ago, the sisters have to play a caregiving/parental role to their Wild Child little sister Ryuuko. Unlike some examples, they do have some help in the form of Aikurou on the side.
- In Kill la Kill AU, we have an eleven-year old Satsuki, with her mother living at a special care facility and her father working constantly. She does note how difficult this can be, especially with the thought of her sisters being taken away from her. However, sadly, the stress of this is what turns her Delicate and Sickly.
- One More Time, One More Chance has Satsuki making an effort at this and goes about some parental motions, after getting custody of Ryuko.
- In The Outside, we have this happen three times to Ryuuko in light of her father's death and her mother's decade-long absence:
- Earlier, we have Satsuki, who is Ryuuko's guardian, however, this is deconstructed as she's, agoraphobia and poor health aside, no more mature than Ryuuko is and isn't too capable a guardian, which gets Ryuuko removed from her care.
- Later, Shiro starts to play this role and he really plays this to a hilt when he tends to give Ryuuko lectures in much the vein a father would.
- Periodically, we have Nui playing something of this (despite being younger) because, due to being sheltered, Ryuuko is more naive than she is.
Kipo and the Age of Wonderbeasts
- The What If? fic Mutes and Humans don't mix has Hugo the Mandrill-Mute escaping the science burrow with an infant Kipo while Song and Lio hold off Dr. Emilia, and follows Hugo's efforts to raise and keep his little sister safe.
- In The Boy Without a Fairy the Great Deku Tree is very hands-off when it comes to raising his children, leaving the childish Kokiri to raise an infant Link by themselves.
- In No Such Luck, No Such Love, Lori promotes herself to parent of the Loud kids after seeing how incompetent Rita and Lynn Sr. are at parenting, especially when dealing with Lincoln's current issues.
- In Sam's Ordeal, Sam had to take care of Simon since they were little, due to their mom being swamped with work at the hospital, and their dad being rendered a passive drunk following a severe workplace injury.
- Her Max: At six, Ruby is forced to become her toddler brother's guardian. She doesn't want to be split up from Max, so she gets her grandmother to talk to Social Services for her. Ruby is unofficially left in control of Max. It's very stressful for a six year old and she spends most of her time focusing on her brother. She worries that he'll resent her when he's older, but for now she's his surrogate mother. Due to his young age, Max can't even remember his mother anymore. Ruby is the closest thing he has to a mom.
- Miraculous Alliance: Since it's just their mother raising them and she often has to take up double shifts to pay the bills, Luka doubles as Big Brother Mentor and the closest thing to a father figure for his sister Juleka, even taking part-time jobs to help ease the load for his mom.
- The AU fic Do You Hear That, Love has Adrien adopting his brother Felix's daughter after he and his wife die in a car accident, some time after Gabriel has also died.
My Little Pony: Friendship Is Magic
- In the Aftermath of the Games universe, the human version of Shining Armor and Twilight's parents were killed by a Drunk Driver when the latter was thirteen. Shining, since he was in his mid-twenties during the time of the accident, took custody of his sister. His fiancee, Cadance, decided that she wanted to help raise Twilight, so they both agreed to tie the knot down at the courthouse instead of doing the big wedding they were planning before the tragedy struck so she could adopt Twilight as well. The two of them agreed to hold off on the wedding and having kids of their own until Twilight graduated high school so they can make sure she spends her teen years in a supportive environment.
- In The Equestria Chronicles, Celestia is as much a mother figure as a sister to Luna, at least at the start.
- Lord Tydal in The God Squad has this happen to him when his mother drops off filly Celestia and foal Luna on his doorstep. He is more than happy to step in and raise the two.
- While known as being one of the gruffer and grumper gods his brothers and sisters (even the ones he didn't raise, like Chrysalis) consider him the father of their large and screwed up family due to their mother constantly abandoning them.
- In the Harmony and Valor universe, the human versions of Twilight Velvet and Night Light died in a semi-truck accident four years ago while on a family road trip. Shining Armor and Cadance have been taking care of Sci-Twi ever since then. During "A Daughter Not His Own," Sci-Twi lets them know on Parents' Day how much she appreciates all that they have done for her and asks if she can call them "Mom and Dad" just for the day, and they pull her into a group hug crying Tears of Joy. Shining Armor even calls her their "beautiful daughter".
- In To Try For The Sun, 12-year-old Celestia and 8-year-old Luna were orphaned in King Platinum's war. Celestia works as a grave-digger to support her family.
- In Son of the Sannin, Itachi becomes this to Sasuke. Shisui also becomes this to an extent, given that in this story he's the oldest surviving Uchiha.
- In Vapors Aiko Uzumaki has a lot of bitterness (at the village) due to feeling that she had to raise Naruto instead of responsible adults. Later, Sasuke discovers that one of his cousins was secretly having an affair, and he has a now-orphaned, academy-student cousin in the village.
- In Ghosts of Evangelion Kaji becomes his little brother's guardian after Heishiro returns from Instrumentality. He thought Heishiro would want nothing to do with him, but his brother makes clear that he refuses to live with strangers.
- Nobody Dies: A large part of Zeruel's characterization is to prevent the extinction of the Angels at any cost, especially after the ADAM fight. That certainly sounds like a parental trait. And with ADAM out of commission indefinitely, someone has to take charge. And with Big Z's anger issues to his siblings (especially those that have defected), it's obvious that not everyone's cut out to be both the parent AND the sibling.
- In Dodger And Company, following the death of Dodger's mother Annie, Rita and Einstein become parental figures to Dodger's younger siblings; while Rita loves the pups, and they love her back, she struggles with the responsibility of raising them, on top of being the gang's de facto leader.
- In Pokémon Reset Bloodlines, Brock is this as in canon, although this time much more seriously since his parents are dead in the new timeline.
- The AU series Guardianship of Bonnie has Clemont forced into this, with support from Ash and Serena, after Meyer dies from a terminal illness he hadn't told them about.
- Yin and Yang Series: Lupapa is perhaps the most egregious example of this trope, having taken care of his seven siblings since her parents' death. Frannie Martin also underwent this towards her younger siblings Oliver and Maggie.
- Aen'rhien Vailiuri: Jaleh Khoroushi mentions to the Aen'rhien's tactical officer that she and her older brother Ehsan ended up as backup parents just from the fact that she was the second of five kids.
- Comes and Goes (in Waves) has Klaus, of all people, stepping into this role for Five after The End of the World as We Know It. He initially denies it, but it becomes fairly obvious fairly quickly that he's fooling no one. Once Five is an adult, he freely admits Klaus raised him.
- A popular Fandom-Specific Plot, affectionately nicknamed "Baby Bones", involves this as a backstory for Sans and Papyrus. It does have some canon evidence to go by—they live with each other and have no other relatives to be seen, they apparently just showed up in town by themselves one day at an unspecified age, and due to Papyrus' immaturity, Sans still performs parental tasks for him such as nursing his belief in Santa and reading him bedtime stories. In some stories it's Played for Drama and used to speculate about their past and the hardships they'd face in such a situation, while in others it's played purely for its positivity.
- FURTHERFELL: Dess has been raising her younger sister Noelle since their adoptive father Asgore was killed, as their biological father Rudy has already passed away and returning to their mother Carol is not an option for unstated reasons.
- Queen of the Swarm: Brian gets legal custody of his little sister Aisha to get her out of their home before their parents screw her up.
- The Truth is out there... and it hurts: Sally takes Samantha's raising in her own hands after they escape from the colonists' prison. They call each other sister, but Sally is more of a mom to her.
- Little Fires: Goosepaw's mother Mousestep gave birth to several stillbirths and then ended up dying in childbirth after giving birth to her only living kit. With no father to raise her, Goosepaw's adult brother Beechfur took over as her father figure.
