According to my notes, Sarah Sealey "Sallie" Chaney, born 17 Apr 1799 in Mississippi, was the daughter of Bailey Eliphalet Chaney and Elizabeth Ratliff. On 28 Apr 1828, she married Howell Joshua Rawlins and they were the parents of Martha, Betsey, Howell J. Jr, and Harvel Rawlings. Sarah's sister Mary "Polly" Ryan Chaney was born 10 Feb 1891 in Mississippi; on 22 Sept 1821, Mary married Hugh Pinkney "Pink" Montgomery in Franklin Co, MS. The parents of Bailey Eliphalet Chaney were William Chaney (b. ca 1833, probably in SC) and (likely but not totally proven) Sarah Norris. The parents of William were James Chaney and (again not yet proven) Mary Johnson (widow Young) - both are believed to have been born in Virginia and migrated to South Carolina before the American Revolution. William migrated ca 1790 to the southwestern area of MS where most of his children settled.
Although I have extensive records about this family (and their 'cousins' who founded Cheneyville, I cannot find any other Rawlings/Rawlins/<other similar spellings> or any Mary E. born about 1795 who might be the lady you mention. Please contact me at firstname.lastname@example.org to swap data.