Au Pair Girl — Judy Klass

Janine Larson is a quiet, responsible kid. But her ditsy friends keep her out past her curfew, and her parents are angry she hasn't found a summer job. They think she spends too much time hanging with her friends and her boyfriend, Dan. Her father arranges for her to spend a month as an au pair girl for Dr. Cargill and his wife; they take their two kids to an island summer vacation home, and Janine goes along. Janine slowly wins the trust of the little boy. She can't get close to his spoiled, snooty sister. But she has bigger problems to worry about, with the rude, unpleasant parents - and the fact that there is something not quite right about the way Dr. Cargill arranges adoptions for "orphan" children. Once the Cargills suspect that Janine knows too much about what is going on, Janine finds that her employers have changed from difficult to deadly . . .