Mamie was the daughter of Hezekiah Briscoe and his wife Mary Jane McMannis. She was the grand daughter of Hezekiah Briscoe, Sr. and Rachael McClain, and Samuel Webb McMannis and Charlotte Shelburne. She married Younger Edward Flynt on 11 September 1894 in Tarrant County, Fort Worth, Texas. Children born in this marriage were Lela (born 1897) and Joseph C. (1899). Since she is completely missing in the 1900 census it is thought that her death may have been associated with the birth of her son Joseph. Her daughter Lela died giving birth to her fist child.