Mary Francis Gregg (maiden name: Garth) was born around 1831 in Alabama to Jesse Winston Garth. Her father was a farmer who owned $75,000 of real estate and $150,000 of personal property by 1860. She grew up in Morgan County, Alabama, and she married John Gregg on August 24, 1858. They lived in Fairfield, Texas, and her husband worked as a lawyer and newspaper owner. By 1860, the family owned $2,800 of real estate and $13,560 of personal property.
During the winter of 1860-61, her husband supported secession and served in the Texas Secession Convention. Her father, however, was a staunch Unionist. Her husband served as a general in the Confederate army, and he died on October 7, 1864.
She settled in Aberdeen, Mississippi, after the war, and she reportedly owned a “large estate.” An Alabama writer declared her a “woman of superior mental endowments and most estimable disposition.” In 1897, she visited her sister in Priceville, Alabama, “in the hope of regaining her fast failing health.” She died there on June 15, 1897.