Who is Denise from Waiting for Normal and what is their importance?

Denise, aka Mommers, is Addie's mother. It is probable that Denise suffers from bi-polar disorder. She seems to ruin most of her relationships with her impulsivity and selfish behaviors. Denise is angry with her ex-husband Dwight, even though he pays her alimony every month and takes care of their two children and Addie. Denise doesn't know how to take responsibility for herself or for her actions. Addie describes Denise's behavior as, "all or nothing." She is not a maternal character and thinks nothing of leaving Addie alone for days without food or supervision. Denise feels that Dwight owes her and blames her problems on everyone but herself.