Whatever Happened To Janie? (Vintage Paperback) by Caroline B. Cooney

How could it possibly be true? But it is true. 

As Janie Johnson glanced at the face of the ordinary little girl on the milk carton, she was overcome with shock. She recognized that little girl - it was herself. . . .

With the mystery of her kidnapping now unraveled, Janie's story continues and the nightmare is not over. No one can bring back or relive the twelve years gone by. The Spring family wants justice, but who is really to blame? The Johnsons know that they must abide by the decisions made, but it's difficult to figure out what's best for everyone.

Janie Johnson or Janie Spring? Who is she? Certainly there's enough love for everyone, but how can the two separate families live happily ever after?