She is enumerated with J.S. Gowdy, self, farmer 30 KY - - Sally Gowdy Keeping House, wife, Married, W 29 AL TN TN Mary Gowdy daughter, F, S, W, 6, TX KY AL
(I researched the Porter descendants living in Etowah County, AL and discovered a Porter cousin with a daughter named 'Sarah' who was 15 b. AL TN TN (1870 US Census, Etowah, AL)I believe this is Sally Gowdy who removed with her parents when they moved to Texas between 1870 and 1880.)
Most likely scenario is that 'Minie" was brought or taken by the Gowdy's following the death of her mother Sarah Selena Adeline Porter in January of 1880.
Family states that Minnie Sappington (15) married G. W. Walker July 5, 1883 (Bible Record); they moved to Oklahoma where he died on June 10, 1905.