Addams grew up in the suburbs of Nashville, Tennessee, the child of the leaders of a religious group she characterizes as a "fundamentalist Christian cult". Growing up she played the fiddle. She served as a combat medic in the United States Navy and the Marine Corps. During her last year in the military, she came out as a transgender woman. Addams chose the name "Calpernia" from the William Shakespeare play Julius Caesar (a variant spelling of Caesar's wife Calpurnia) and from its appearance on a tombstone in the film The Addams Family.