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

Mary was Annie's sister. Annie remembered her sister crying as a child because she missed their father. Now it was Mary who helps to take care of Annie. She took Annie to the hospital when she had her break down. Mary also was the one with whom the doctors discussed Annie's prognosis and her treatment. Mary admited that she felt overwhelmed and unsure about making these decisions about her sister's health. Generally, Annie realized when the doctor was speaking with Mary about serious matters and was able to come to herself enough to let her own wishes for her treatment to be known.