Kaitlyn Dever Brynn Elizabeth Kaluev Young Brynn Zack Duhame Mailman Lauren L. Murray Brynn's Mother Geraldine Singer Mrs. Collins Dane Rhodes Police Chief Collins Evangeline Rose Young Maude Dari Lynn Griffin Maude Emani White Teenage Cashier Tenaj L. Jackson Woman at the Swings Nathalie J. Alarcon Neighbor (uncredited) Ginger Cressman Celebration Guest (uncredited)