True Believer — Virginia Euwer Wolff

LaVaughn is fifteen now, and she's still fiercely determined to go to college. But that's the only thing she's sure about. Loyalty to her father bubbles up as her mother grows closer to a new man. The two girls she used to do everything with have chosen a path LaVaughn wants no part of. And then there's Jody. LaVaughn can't believe how gorgeous he is...or how confusing. He acts like he's in love with her, but is he?