Promises (Sweet Valley High, #15)

Bad girl in town ...

Steven Wakefield is crushed when his girlfriend, Tricia, dies after a tragic illness. The only things that keep him going are the memory of their love and his promise to Tricia to take care of her sister, Betsy, after she's gone.

Betsy Martin's wild exploits with drink, drugs, and boys have left her with the worst reputation in Sweet Valley. But when Steven takes her into the Wakefield home, Betsy makes a promise to change. And as her goodness grows, so does her love for Steven.

Jessica, Steven's conniving younger sister, doesn't like this one bit. She makes a little promise of her own to get Betsy out of the house and out of Steven's life... forever!