A beat cop, she was married to Mike Foster for a number of years and in the process, gave birth to Brandon. When Brandon was five, having come to the realization of her own sexuality, she divorced Mike and became involved with Lena. Later, they fostered then adopted the twins. In the family, she takes on many of the traditionally male roles - stern parent, bill payer, and so forth.
Berserk Button: Her lesbianism and Lena. When Brandon calls her out on (among other things), that he had no choice in the matter of having two moms (he was five when his parents divorced), Stef quickly loses her cool. Only the fact that Brandon storms out of the house and Lena jumps in prevents her from saying something she might regret.
Freudian Excuse: Seems to have confidence issues in regards to her relationship with Brandon.
Good Cop/Bad Cop: In the parenting sense, Stef tends to play bad cop and overall is a lot stricter than Lena. Kinda plays into their parental names - Stef is "Mom" which is more formal while Lena is "Momma" which is more casual.
Ironically, later events in the first season play with the label. We find out that she lies to Internal Affairs about her shooting. Her shooter shot her by accident and dropped their gun in shock which causes it to fire a second time; Mike comes in and, assuming he was still armed as it was a dark room, shot in return. This is an issue because, legally speaking, Mike just shot an unarmed man.
The Nicknamer: Calls Brandon "B", Mariana "Lovely", Jesus "Love", and so on and so forth.
Open Minded Parent: Is willing to buy her son Brandon condoms and give Lexi the morning after pill Jesus bought.
Portrayed by: Sherri Saum
A vice principal, Lena is the heart of the family and takes on many of the traditionally female roles in the family - cooking, cloths shopping, organization.
Ambiguously Brown: At first, though it's eventually revealed that she has a black mother and a white father.
But Not Too Black: Her mother is of the opinion that darker-skinned blacks have it harder than light-skinned blacks. This extends to interracial people like Lena who can be called both black and white (having both as parents). Right or wrong, her mother proceeds to say the following:
"You will never know what it's like to be a black woman in America."
Embarrassing Nickname: she had two in high school: "Oreo" (because she was biracial) and "Klondike Bar" (after she came out as a lesbian)
Reasonable Authority Figure: Fights to keep Jude in school even though he's woefully unprepared for the tests that the school has to give to maintain funding and she realizes that Jude skipping past the waiting list could seem like Nepotism. The reason she does so is that she realizes that separating Jude and Callie again would be tramatic for the both of them and that the reason Jude is behind to begin with is because he's had practically no educational stability.
Screw the Rules, I'm Doing What's Right: When Jude misses the required 65 on the exam to stay in Anchor Beach by one question, she changes one of his answers so that he passes. That said, she's definitely conflicted over it.
Wicked Stepmother: Averted. She's really nice and Brandon considers her his other mom - more so than he considers his biological dad his dad. That said, bio-dad thinks of her in this way and seems intent on undermining Lena's relationship and authority over Brandon. Likewise, Jesus and Mariana consider her their mom.
Portrayed by: Maia Mitchell
A youth in the foster system, Callie and her brother Jude have bounced from home to home. Over the course of four years, they've been in at least seven different homes before ending up with Lena and Stef. As a long term foster child that's been in some questionable homes, she's learn to live apart from others and trust even less.
Broken Bird: By the start of the series she has already given up on finding a family who would adopt her and Jude or even try to defend herself when someone blames her for anything.
Dark and Troubled Past: Callie is fresh out of juvie, though if the pilot is any indication, she doesn't really have any sort of rebel streak. The people she's lived with before the Fosters and her birth parents, on the other hand, may have been less than stellar.
Despair Event Horizon: the reveal that her biological father had been released from prison since over a year was enough to make Callie cause trouble in a shop and make the owner call the police
Mama Bear: Despite not being Jude's mother, she tends to fill this role in his life
Noble Bigot: She is mildly homo/transphobic, as she worries that Jude acting different will get him beat up. That said, since Jude has been beat up before and she's been raped, there's a certain level of Freudian Excuse going on since she has zero issues with Stef and Lena; it may very well be that she's not bigotted but just excessively worried about her brother getting injured or worse.
Mariana's twin brother, Jesus is the free spirit of the kids. That said, he's just as studious as his siblings and in many ways, a lot more wise and responsible. Often however his desire to protect his sister get in the way of him doing things for himself.
Attention Deficit... Ooh, Shiny!: Relatively speaking, realistically portrayed. Impulsive decisions, an inability to keep track of simple things (like remembering to take his medication, as in the second episode), and often forgetting what's been told to him (such as multiple reminders about skateboarding in the house) are common symptoms of ADHD.
Foolish Sibling, Responsible Sibling: Initially appears to be the foolish sibling to Mariana's responsible sibling, but is actually revealed to be the more responsible one. In the pairing of Jesus and Brandon, it's more straightforward.
Happily Adopted: To the point where he's pretty offended that Mariana is too embarassed to dance with their moms during the father-daughter dance of her quinceanera - though the fact that Mariana also asks Mike (Brandon's biological father) of all people doesn't help.
Honor Before Reason: Partially as a side effect of his ADHD (it makes him more impulsive in the moment), but he tends to be pretty overtly protective of those around him in the most direct way possible even if it's maybe not the smartest approach. He offers advice to Brandon, stands up to a jock twice his size who's hassling Lexi, and spontaneously takes the blame for selling his medication instead of Mariana.
Portrayed by: Cierra Ramirez
Jesus's twin sister, she's the girl of the house whom everyone else babies. Not that she minds, as she enjoys the attention. Though on the exterior, she's a studious and straightforward girl, her internal insecurities often compell her to make less than wise decisions and clam up about issues.
Bratty Teenage Daughter: Is willing to sell Jesus' important medications for money. Then lets her siblings take the fall for doing so when caught - first Callie (who doesn't resist since she's learned from previous foster parents that her status as an outsider gives her zero credibility), then Jesus (who takes the bullet to protect her).
It's All My Fault: Twice. The first when Lexi's parents discover she had have sex and when Jose goes to their biological mother's house and Stef gets shot when she went searching for him.
Karma Houdini: Didn't suffer any consequences over selling her brothers medications. Subverted when Jesus sneaks off to help their birth mother get into a shelter for battered women. His disappearance causes her to confess to her moms what she's been doing. This results in Stef getting shot when she and Mike go to Ana's house to look for Jesus.
Mommy Issues: Not with her moms but with her birth mother. But it does spill over into her relationship with her moms. When she feels guilty that Callie has taken the blame for something she's done, she tells Jesus that if she confesses, she fears that Stef and Lena will stop loving her. As the first season evolves, this becomes a regular thing we find that she worries about.
Playing Sick: Apparently does this a lot, to the point where no one believes she's actually sick in the pilot.
Spoiled Brat: Refuses to be happy for her friend and her brother simply because it will ruin her party. That's the entire reason why they didn't want to tell her before the party. For some extra context, Jesus was initially reluctant to have the relationship to begin with because of Mariana. Also, of course, Jesus and Mariana are twins - he graciously gives up any sort of celebration for himself so that Mariana can have her quinceanera.
Portrayed by: David Lambert
Stef's biological son with Mike. The eldest son, he tries very hard to fly the straight and narrow. But when Callie enters the family, things change for him.
Foolish Sibling, Responsible Sibling: Nominally the responsible one against Jesus, but in the second part of the first season seems to be becoming more irresponsible especially in regards to his feelings with Callie, thus causing her to run away from the Fosters, and then telling his mothers about it later on.
From Bad to Worse: Practically almost every action Brandon does ends up turning an already bad situation that he caused into an even worse situation.
Genre Blind: It takes his brother Jesus (nominally the rebel between the two) to point out that when your girlfriend catches you hanging out with another cute girl (who also happens to be living with you for the indeterminate future), your girlfriend will probably be jealous in the least. Jesus later suggests Brandon do something big and nice for Talya in compensation, to which Brandon ultimately stands up Talya in order to hang out with Callie.
Took a Level in Dumbass: Throughout the first season. At the beginning, he's an honors student like Mariana who has no trouble with the law or school. In the season finale, Brandon has been arrested and is almost expelled from school. He also kisses his father's girlfriend (possibly ex-girlfriend at the time; it's a little unclear).
Ambiguously Gay: and Ambiguously Trans, as well—he's a bit too young for such things to be apparent as of yet, but his sister is certainly concerned he's going to get beaten up by people who perceive him as "different." Becomes slightly less ambiguous in the season finale, when Jude admits to feeling jealous about Connor liking a girl named Maddie.
Book Dumb: Primarily because he's been in seven schools in four years but there's subtle suggestion that he may have some sort of learning disability.
Broken Bird: A more subtle example than Callie. His bad experiences with foster homes have developed a fear of being taken away for being anything but an Extreme Doormat
Extreme Doormat: Deconstructed. His to keep quiet and just agree with what other people say comes from a fear of being expelled from the foster home.
Wholesome Crossdresser: We only have one instance of this so whether it's a one time thing or not is unclear. But his previous foster dad caught him goofing around with a dress and promptly started to beat the crap out of him. This is what prompted Callie to beat the crap out of the guy's car with a bat and land her in juvie.
Wise Beyond His Years: He notices the flirting between Jesus and Lexi, makes a double sided comment to Jesus about it, and picks up on Talya's antics. But like with Callie, he's learned to not say anything.
Portrayed by: Danny Nucci
Stef's ex husband and fellow cop. The loss of his wife to another woman still stings him, though he tries to be as civil as possible about it. Nevertheless, he still struggles to keep Brandon, his son, in his life.
The Alcoholic: He is a functional one, though barely at that. In the past, his divorce tipped him over the edge. In the present, Stef's shooting may result in a relapse.
Armor-Piercing Question: On the receiving end of one from his biological son, Brandon, who calls him out for being so distant and not really having a strong relationship with him (not to mention, antagonizing Lena, who Brandon likes).
Cool Uncle: Has shades of this with the other childrens.
Parental Neglect: He admits that since he considers Stef and Lena excellent parents, he had been neglectful of Brandon.
The Rival: It's unspoken but clear among all parties that he considers both Lena and her relationship with his ex a challenge. Whether it's mild homophobia, a sense that he failed in a relationship, or that he still has feelings for Stef is unclear and it may be all of those reasons and more.
Portrayed by: Madisen Beaty
Brandon's girlfriend at the start of the series. At first, she seems like your normal typical girl next door. But the arrival of Callie throws a wrench into her world and she doesn't take it well.
Alpha Bitch: To an extent. She spread rumours that it was Callie, not Mariana, who was selling pills and snooped around Callie's things to find anything that might be useful to her. All in an attempt to maintain her relationship with Brandon/drive Callie away.
Bitch in Sheep's Clothing: Is perfectly nice to Brandon, but seems to be doing all she can to get Callie sent away. Every time any of their conversations steers toward Callie, she asks, "Has she been sent away yet?" However, if the trailer for the next episode is any indication, Brandon does eventually see through her act.
He does. They break up. Whether she'll be back to wreck havok remains to be seen since she also revealed some of the information she gathered on Callie's past to him.
Clingy Jealous Girl: Though in her defense, Brandon unintentionally does things to strain their relationship. On the other hand though, this doesn't excuse her catty behavior.
Jerk Ass: she occasionally has flashes of being a nicer person, but Callie seems to bring out the worst in her, even after she and Brandon break up
Portrayed by: Alex Saxon
Liar Revealed: The first house he brought Cali to wasn't his. Especially bad seeing if Cali got caught, she'd be in juvie.
Wild Teen Party: Throws one before he moves out of his old house, his family having been foreclosed on.
exploited by him. He wanted people to ruin the house as revenge for being taken from them when his mother worked so hard to buy it.
Portrayed by: Bianca Santos
Beware the Nice Ones: when she discovers she and her parents are undocumented she exploits it to blackmail her parents so she isn't sent to another school
Satellite Love Interest: For Jesus. We really don't know much about her other than the fact that she's Mariana's best friend.
What the Hell, Hero?: Calls out Jesus on the fact that he's not pursuing their attraction to each other purely because Mariana told him not to without any real reason other than that they're friends.
Portrayed by: Brandon W. Jones
Jerkass: Made Callie and Jude lose the best foster house they had when he seduced Callie, threaten Callie when she tried to warn another girl they had brought to the house and Raped Callie when they still lived with his family
Karma Houdini: He has suffered no consequences for his actions against Callie.