Ethel had a short and unhappy marriage to Jack Byrne, a glassworker. They had two children, Jack and Olive. In 1906, Ethel left her children in the care of their paternal grandparents to protect them from their abusive father; Ethel only visited her daughter once in sixteen years. Olive grew up to become an important muse to the creator of Wonder Woman, William Moulton Marston, and more details of Ethel Byrne's life came to light when Jill Lepore wrote about the superheroine character in 2014.