Tonya is 9 year old artist and a spoiled, smart-mouthed, complaining, manipulative, and vain youngest child of the Rock Family and the antagonist of her older brothers. She bothers Chris more than she bothers Drew.
As the youngest sister of Chris and Drew, she is able to get anything out of her father. Ever the troublemaker, Tonya is often seen causing trouble particularly for her siblings (such as by snitching on them) while getting away with trouble herself. This is referenced in "Everybody Hates Greg," when Tonya's trouble-making nature causes Chris to visit Greg's after school in order to avoid going home. Her father is over-protective of her and when she got a boyfriend, he becomes very suspicious.
As a result, Tonya gets into trouble twice when she blames Chris for a misdeed and he is not there. Despite her behavior, she usually gets what she deserves. She is a huge fan of Billy Ocean (to go as far to say that Michael Jackson stole the Moonwalk from him) and Danny Glover.
Her favorite football team is The New York Giants. Tonya is the special child and therefore gets whatever whenever she wants it. She gets out of trouble by giving her parents (or in this case Julius) a sad look and a cute voice, "I'm sorry, mommy/daddy!"
- She was originally a Noki, but when the show left Los Angeles and moved to Burbank (as well as Warner Bros. owning the series) she becames a Pianta.