I would say that one major conflict is Janie's internal struggle of what to do when she realizes that she was kidnapped from her original birth parents. She sees her own face on the back of a milk carton, and that's how she figures it out. Her struggle is then what to do about it. On one hand, she wants to find her biological parents. On the other hand, she has her adoptive parents who love her very much and are the only family that she knows.
A second conflict begins after Janie sees her birth family. She writes a letter to them, but doesn't mail it. Janie is struggling with whether to ignore the evidence or tell her adoptive parents. Should she contact her birth family or not?
A third conflict is between Janie and her boyfriend Reeve. It's not a major conflict and doesn't involve them fighting, but the decision of whether or not to begin having sexual relations is a small conflict in the book.