Leslie Thompkins made her first appearance in Detective Comics #457, in which she is depicted as comforting the young Bruce Wayne on the night that his parents were murdered. Inspired, she dedicates her life to helping slum kids avoid a life of crime. Every year on the anniversary of his parents' murder, Batman visits Leslie in Park Row (which was now referred to as Crime Alley). However, Leslie has no idea he is the boy she had helped decades before.