In the 1920s, she went to live in Paris, divorcing her first husband J. Eugene Mullins.
[1] The pair endured the Nazi occupation of Paris as enemy aliens under house arrest.
Around that time, Briffault began working with Vilhjalmur Stefansson to research the history of Russian-American attempts to join Alaska and Siberia by telegraph.
Briffault worked as an assistant editor for Las Americas Publishing Company from 1957 to 1969.
At the end of her life, she was living in New York City, where she died at St. Vincent's Hospital on August 13, 1981.