The Woman In White by Wilkie Collins: I highly recommend this large tome. It's worth your time. I love a mystery that I am unable to unravel until the author allows. And this kept me rapt until the last.
YES!!!! Suzanne -- EXACTLY!!! Anything created for children, a book, a movie, whatever, that doesn't also entertain adults is poorly devised. I have enjoyed Margaret Brown's "Goodnight Moon" through two generations and three children. I never tire of it.