Was Manerva Bean Cherokee?

Having a hard time finding family info on my 3 X great-grandmother, Manerva. (Munerva? Minerva?) I was told that she was full blooded Cherokee, but the only 3 Census records I’ve found, list her as being white. She could be from Meigs Co., White Co., Putnam Co., or Jackson Co., all in Tennessee, Her birth date is around 1821, and date of death is 1877, in White Co., Tennessee. I am unable to find any information about her mother and father and possible siblings. She had a son who was born in Arkansas, by the name of Robert Aarons. Her daughter with husband, John McKinley, (30 yrs older than Manerva, and from VA) is Mary Elizabeth McKinley Tallant. She was unable to read or write, and signed her will with an “X.” The only other thing that I know, is that she also raised her husband John’s children from his previous marriage, due to his first wife’s early death. I would really appreciate any info at all about Manerva’s parents and/or siblings, and whether or not, she was Cherokee. Thank you.