Smart Enough To Know — Eileen Goudge

She's a wildcat in disguise....

Elaine's closest friends -- Kit, Alex, and Lori -- are the only ones who know that she is also the rowdy school mascot, Wilbur the Wildcat. To the rest of the school, she is shy, soft-spoken Elaine Gregory "the Brain."
So when she's asked to tutor handsome Rusty Elaine is excited, but terrified. Flirting with the popular football player is easy when she's dressed as Wilbur, but will Rusty ever see anything romantic in plain old Elaine?

To make matters worse, things at home are very tense. Elaine's whole life has changed since her father lost his job, and she can't figure out what to do -- even though everyone thinks she's SMART ENOUGH TO KNOW.