One of the earliest female syndicated cartoonists, Dumm was born in Upper Sandusky, Ohio, and lived in Marion and Washington Courthouse, Ohio throughout her youth before the family settled down in Columbus. Her mother was Anna Gilmore Dennis, and her father, Frank Edwin Dumm, was an actor-playwright turned newspaperman. Dumm's paternal grandfather, Robert D. Dumm, owned a newspaper in Upper Sandusky which Frank Dumm later inherited. Her brother, Robert Dennis Dumm, was a reporter for the Columbus "Dispatch", and art editor for Cole Publishing Company's "Farm & Fireside" magazine.