What are the motifs in The Murderer's Daughters by Randy Susan Meyers?

Childhood trauma is a recurring idea. This book is about the trauma that shaped the lives of the two main characters, Lulu and Merry. Lulu finds herself living with guilt her whole life as a result of allowing her father into the family apartment despite her mother's express wishes to the contrary and her hesitation in going for help when her mother asked for it. Lulu feels that if she had behaved differently that day her mother might still be alive. Unfortunately, the reader believes that the volatile relationship between Lulu's parents more than likely would have led to disaster no matter what Lulu's role.