Gwenny Thompson is a recurring character/main antagonist. She is portrayed by Kerri Medders.
She started to treat Katie better when she thought she had cancer and did the same with Alexa when it was her the one who had the illness, but told her “I’m only treating you like this because I won’t stop being popular”. Alexa doesn’t like being treated kindly by Gwenny because it is not her real personality, so she achieves to make her hate Alexa so much that she goes again to her normal behavior.
In the episode #GWENCAS, It is known that Gwenny and Alexa's brother, Lucas, go to Cooking Class together. Gwenny doesn't like Lucas, but Katie doesn't agree and finally, for Alexa and Katie's disgrace, Gwenny and Lucas become a couple. When Gwenny comes to Dave, Lori, Alexa and Lucas's house, she brings cupcakes. All the family is surprised about how delicious the cupcakes are, and she says they were baked by her. Lori asks her what do they have that makes them so delicious and she says it's a pinch of nutmeg.
When Season 3 begins, Alexa tells Katie Lucas and Gwenny broke up. They don't like each other but Gwenny sits with Alexa, Katie, Hannah and Reagan at lunch. Alexa really doesn't mind what Gwenny does, as it doesn't affect her.
She was a bit nicer but still selfish and rude. Everyone hates this attitude, but they just stop listening to her.
"I don't want some rando messing up a picture with me."
"I can't control the world's problems but I can control wrinkles."
"I don't factor into this... so I'm gonna go. Prom pedicures, anyone?"
S1: E1 Bad Hair Day
S1: E3 Basketball
S1: E6 Picture Day
S1: E9 Winter Luau
S1: E13 Winter Formal, Part 2
S2: E1 Second First Day
S1: E3 #GWENCAS
S2: E4 Tryouts and Latte Doubts
S2: E5 PB Without J
S2:E6 Shop 'Til You Cry
S2: E10 Sweet Sixteen
S3: E1 1st Day of Junior Year
S3: E4 Unconsciously Coupling
S3: E7 It's Just... Weird
S3: E9 Last First Day
S3: E12 Choose Your Own Adventure
S3: E15 Last Dance
Gweeny Thomson is very mean to Alexa and Katie in season 1. By season 3 she joins the friend group and stops being so annoying. In season 1 Gwenny tried being really nice to Alexa and treating her too nicely all because she has cancer. In Season 2 Gwenny dates Alexa’s brother Lucas Mendoza. Gwenny is pretty annoying, popular, and only does things to be cool. She is pretty snappy and often rude in the first couple of seasons. She likes to be well organized and clean.