YA book about girl who finds out she has superpowers and has to hide them in high school

[Anna Sophia]

The book was about a teenage girl who finds out she has superpowers while in high school and has to keep them a secret but also ends up using them in different ways when needed, i.e. to foil some kind of plot centred around prom. Sort of like the premise to the movie 'Sky High' but focused just on this one girl. I remember the cover being a bright yellow with (maybe) a cartoon illustration of a girl on the front. It was published in English with the book set in a US city in modern times. I believe it was written by a female author but could be remembering it wrong. Style-wise it was written in a way that reminded me of Meg Cabot.

I borrowed the book from my local library somewhere between 2004-2010, from what I remember.