Tilly seems to be a very crazy girl, as she has held a gruge over Ally for over 10 years. Tilly will do anything to get what she wants and won't let anything get in her way.
She claims to hate Ally, because in kindergarten, Ally wrote "The Butterfly Song" which was chosen to be in the pageant instead of Tilly's "Ladybug Song". Because of this, she blogs embarrassing stuff about Austin, figuring if she tries to ruin his career, she will ruin Ally's as well. She claims she is a master of disguise and is able to disguise herself as a baby, a catfish and a recycle bin. She also still seems to believe that her song was better than Ally's. She eventually uses Ally's stage fright against her and attempts to force Ally to sing "The Butterfly Song" in front of the mall or else she will keep posting bad stuff about Austin in order to destroy his career. Luckily, Austin sings the song for her, and Tilly accidentally admits that she is H8TER girl and she made everything up. Austin, Ally, Dez and Trish are later seen watching a video of Tilly destroy the mall stage. Trish mentions that Tilly took her blog down in embarrassment and hasn't been seen since.
- She hates when she reveals things even though they're true.
- She's good at disguises.
- She owns Miami H8TER Girl.
- She has known Ally and Trish from Kindergarten.
- She is often described as...insane or crazy.