Who was the first to address Atticus by his nick name?

The first character to address Atticus Finch by his nickname, "One-Shot Finch," in Harper Lee's "To Kill a Mockingbird" is Miss Maudie. She refers to him this way while discussing his exceptional marksmanship skills, which becomes a notable aspect of his character throughout the story. This nickname highlights both Atticus’s past and the themes of skill and morality in the novel.