Who is Lilly from A Million Little Pieces and what is their importance?

James's love interest, Lilly, is an ex-prostitute with addictions to crack and Quaaludes. She has been sexually abused and abandoned for her entire life and only trusts her grandmother and, ultimately, James. She came to the Clinic after a horrible gang-rape that she suffered at the hands of her boyfriend and many of his drug dealers. Regardless, she remains a rock for James, acts as a calming force when James battles the Fury, and speaks comfortably of many of the tragedies in her life. In return, James is a comfort to her in times of great fear, as when she finds out that her grandmother has cancer.