- Age Lift: The animated series ages them up a year from the comics.
- Foolish Sibling, Responsible Sibling: Marine is impulsive, fun-loving and somewhat naive while Wendy is more level-headed and intelligent. Somewhat justified in that Marine is only seven while Wendy is a teen.
- Paper-Thin Disguise: "Princess Marina" and "Princess Wendynoodle" are just Marine and Wendy with different clothes (and in "Marina's" case, a new hairstyle).
- Person of Mass Destruction: Wendy and Marine normally end up causing large amounts of property damage. In some episodes, they even manage to destroy their entire neighborhood.
- Strong Family Resemblance: Even though the show averts the Only Six Faces trope, the Sisters are identical except for their hair and clothes. One episode even had someone describe Marine as a short, blonde version of Wendy.
The older of the two sisters. She's a 13-year old (12-year-old in the comic) Phoneaholic Teenager who is the most popular girl at her school, and is a typical teenager who loves her boyfriend, music, celebrities, and makeup.
- Alpha Bitch: Averted. She's friendly and kind despite being the most popular girl in school.
- Beware the Nice Ones: She may be nice, but there's a reason everyone is terrified of making her angry
- Big Sister Instinct: Wendy shows this to Marine when she is in trouble or in danger.
- Book Dumb: Her scores on tests for a hundred points are single-digit numbers.
- Butt-Monkey: Other than Maxence, she suffers most of the show's Amusing Injuries.
- Cool Big Sis: Wendy can sometimes be one to Marine, Depending on the Writer. In these cases, she helps Marine with her problems and gives her good advice.
- Foolish Sibling, Responsible Sibling: The responsible sibling to Marine's foolish sibling.
- Informed Attractiveness: She is said to be one of the most beautiful characters in the show.
- Phoneaholic Teenager: She is almost always on her phone.
- Popular Is Dumb: Zigzagged; she's Book Dumb and occasionally does rather idiotic things, but is smarter than some of the other characters and some of her plans work fairly well.
- Zany Scheme: She often comes up with outlandish, sometimes idiotic plans to achieve her goals.
Otherwise known as Maureen, Marie, Marina and a host of other names, Marine is Wendy's seven-year-old sister who loves annoying Wendy. Her naivete and stupidity tend to land the Sisters in trouble.
- All Girls Like Ponies
- Annoying Younger Sibling: One of her favorite hobbies is to deliberately annoy Wendy.
- Children Are Innocent: Zigzagged; she's not as innocent as other children, but still believes in magic and fairies and other things like that.
- Dub Name Change: Maureen in the English comics, Marie in the English dub, and Marina in the Italian dub.
- Dumb Blonde: While much of her stupidity can be attributed to her young age, one of the comics suggested that shell still be an idiot when she grows up.
- Girly Girl: She loves princesses, fairies, unicorns, ponies and sparkly things.
- It's All About Me: She rarely does anything to help Wendy unless it benefits her in some way.
- Malaproper: She makes up words like undestroyable and she also gets confused with words starting with vowels; for example, she thinks an animal is a nanimal and refers to animals as nanimals.
- Puppy-Dog Eyes: How she convinces Wendy to do anything for her.
Wendy's boyfriend. He's a Nice Guy, but also not very bright.
- Dub Name Change: In the English dub, hes called Maxwell, or sometimes just Max.
- Dumb Blonde: A rare male example. Hes even dumber than Marine.
- Informed Attractiveness: He is apparently very attractive in-universe, as multiple girls other than Wendy have tried flirting with him.
- Nice Guy: Hes genuinely one of the nicest characters the show has to offer.
Wendys best friend, who is much more calm and collected than anyone else and is the Only Sane Woman of the Sisters friend circle.
- Never Bareheaded: She is never seen without her yellow hat.
- Only Sane Woman: Wendy comes up with a new crazy Zany Scheme every day, Marine is naive and childish, Max is an idiot, and Sammie is normal.
- With Friends Like These...: To Wendy in Quelle Soiree, and how. She uninvites Wendy from a party, invites Marine in her place, and tries to flirt with Max (ignoring the fact that hes Wendys boyfriend).
One of Maries two best friends.
The second most popular girl in school. She hates Wendy for being more popular than her and will try anything to make Wendys life miserable, though Wendy usually winds up winning.
- Alpha Bitch: She's the second most popular girl in school and is a rude, snobby brat who loves making fun of people and has a group of followers who used to be Wendy's followers.
- Fiery Redhead: She has a really short temper.
- Informed Attractiveness: She wears braces and has a nasally voice but is apparently supposed to be pretty. Some of the kids even think she is prettier than Wendy.
- Jerkass: She often brags about rude or mean things she has said to other people.
- Manipulative Bitch: One episode has her manipulate Marie into turning against Wendy and doing her work for her.
The Sisters mom, a level-headed hospital nurse.