It does not really matter if Lucy believes that her ancestors are cursed (she does) because she is sane and rational, and this will not affect her. And she has foster parents who love her, and surely that will make a huge difference.
Her mother, Miranda, abandoned her as a child, after suddenly going mentally insane. Periodically she shows back up, singing the old Simon and Garfunkel song "Scarborough Fair". It isn't until Lucy finds the journal pages her mother hid for her long, long ago, that she begins to understand...each generation is to complete three impossible tasks before the birth of her first child...or sink into a deep madness. But Lucy knows that this will not happen to her. Though her due date is drawing closer, she has it under control...until her control slowly slips away. Loved this book!