Rachel was the daughter of John and Elizabeth (Simpson) Smith.
Rachel married Lewis Medlin in 1793. Their children were William (died young), Susannah, Nancy, William Owen, Elizabeth, Mary Ann, Marion Hall, Melissa, Thomas "Jarret", Sarah Ann and Luisa.
Lewis and Rachel were among the first members of the New Hope Baptist Church of Bedford County, Tennessee, organized 1st April 1809. (Ref. Tennessee Archives at Nashville, Tennessee.)
Lewis Medlin had an unsuccessful land draw in Franklin County, Georgia in 1805, moving the family and living there briefly.
Rachel and Lewis were members of the Cole County, Missouri United Baptist Church (now Moniteau County, Missouri) called Green Grove, which still exists in 2010. They organized a United Baptist Church in Platte County, Missouri, where Lewis died.
When Rachel moved to Texas with her daughter Susannah and her husband, Ambrose Foster, she brought their Bible and the vessel used for the Lord's Supper, among other records. This vessel is still owned by the Lonesome Dove Baptist Church which they organized in the area now Tarrant County, Texas.