I have a Mary Ann Davis in my line but showed her husband only as a "Mr. Sheets". I'm thinking she is very possibly the one you are researching. My Mary Ann was born circa 1832 in Ross Co, Ohio, the daugter of Samuel and Rachel (Colbert) Davis. My 3rd great-grandfather was Mary Ann's brother, David. More siblings were born after they moved to Covington, Fountain Co, Indiana. The whole family moved to Coles County, Illinois.
Sam Davis was the son of Walter and Mary (Tracey) Davis, both born in Virginia. Walter fought in the Revolutionary War and he and Mary died in Jackson/Ross Co., Ohio.
I have lots of Davis info. Please email me if you feel we have a connection here.