Who is Sarah from A Shining Affliction: A Story of Harm and Healing in Psychotherapy and what is their importance?

Sarah was one of Annie's closest friends. Shehelped to arrange Annie's surprise birthday party prior to her break down. Sarah also helped Annie's sister, Mary, take her to the hospital, and later picked picked her up from the hospital, transporting Annie to the house where she would be staying. Annie told Blumenfeld that it was Sarah who held her so that she could go to sleep during her most stressful times with Melanie. Sarah also accompanied Annie to her final appointment with Melanie.