The Ainsworths who were in these counties were the children and grandchildren of David A. Ainsworth & Elizabeth Garrett. (David was the brother of my 3rd great grandfather.)Most of this family is pretty well documented but there are two possibilities for the parents of your Mary Ann. David's son William H. Ainsworth married Agnes Hill abt. 1859.The family tree shows that they had one daughter, given name and birthdate unknown. David's son Elbert G. Ainsworth married a woman only identified as M. M. on the 1860 census.Elbert recorded 40.68 acres in the Union Co. land records on 4/1/1861.He fought for the 24th Arkansas Infantry, CSA and was captured at Arkansas Post on 1/11/1863.He died at Camp Douglas, IL in March, 1863.There is no record of children for this couple, but they could possibly have had a child. As far as Indian blood, one of David's other sons is known to have married a Choctaw woman and another married a Cherokee woman.These two moved to the land of the Choctaw Nation in OK.There is a possibility of David and his brothers being part Indian but this is unproven and may never be proved. You might want to search the 1870 Census for Union Co. and Columbia Co. for your Mary Ann as an 8 or 9 year old. If you want more information on David's family, contact me.