Wendy’s sister. Aileen was struck by a car and killed when she was six years old and Wendy was 10. Wendy thinks about Aileen in the waiting room at Dr. Edmonds’s office, and Danny—from inside the exam room—reads Wendy’s thoughts. Wendy thinks that it was Aileen’s death that caused her mother to turn into such an unpleasant woman, which ultimately ruins Wendy’s relationship with her mother.