Dorothy is Dibs’s younger sister. Dibs’s mother often describes Dorothy as a “perfect child,” and she and Dibs do not get along. Because of this, Dibs’s parents send Dorothy away to a boarding school during the week. Dibs expresses hostility toward Dorothy during his play sessions, as well as toward their mother and father. He sometimes wishes that Dorothy would get hurt, and he talks about poisoning her. Over time, however, Dibs becomes more empathetic toward Dorothy, explaining that it’s probably lonely to spend so much time away from the family. By the end of his sessions, he also takes the nursing bottle and holds it up to the “sister” doll’s lips, illustrating a new sense of responsibility and deep care for Dorothy.