Earwig and the witch
by Diana Wynne Jones, Paul O. Zelinsky, Miho Satake, Magali Mangin
Although an orphan, Earwig has always enjoyed living at St. Morwald's, where she manages to make everyone do her bidding, but when she is taken in by a foster parents who are actually a witch and a demon, she has a hard time trying to turn the situation to her advantage.
