@Robert Gentel,
Offhand, the parents - perhaps just one of them - are mentally ill in some way, perhaps not re the book. I may be wrong and this is plain rampant ignorance.
I'd guess at least one parent and probably both had weird/horrible upbringing.
Clearly abuse, whatever the ultimate fault, but I wonder about the chain of circumstance if not causation, and if there is more beyond this suffering girl.