Noticed that this Mary has conflicting parents attached. Ancestry Hints show her parents as William Gibson and his Mann wife. The 1870 census shows her mother's name as Ann, not Hettie.
1870 United States Federal Census
Census & Voter Lists
Name Mary Gibson
Birth abt 1865 Alabama
Residence 1870 Township 6 Range 1 District 50, Gurleysville, Madison, Alabama, USA
Father William Gibson
Mother Ann Gibson
and the 1880 census shows her mother as A. M. Gibson (i.e., Ann Mann Gibson):
1880 United States Federal Census
Mother A. M. Gibson