I would think a DNA test would be definitive, but that never gets discussed or demanded.
My grandma told stories that we had Indian blood in the family, down from a long line of originally French-Canadian people who came down to Indiana in the 1700s. My brother ran with that and posted stuff on Facebook with all sorts of Indian themes. Anyway, I did the Ancestry DNA test, came back zero native American. At least my brother has reduced his “native spirit” type postings.
DNA test not required. Cherokee genealogists have done the math and Warren is zero Cherokee. She had an ancestor who shot an Indian for not being respectful (the Indian was drunk at the time) and she has an ancestor who rounded Indians up and forced them into the infamous Trail of Tears. Of actual Indian blood she has not a speck.