Mary A Hardeman born AL c. 1840 + Davis

Searching for any information on Mary A Hardeman, Hardaman (unsure of spelling) who was born in AL, lived at some point in Barbour County, and married James Jackson Davis. Family story says Mary was full-blooded Cherokee, and pictures of her descendants seem to bear out native ancestry somewhere in the family. Please help! I have next to no information on her prior to her marriage.