Since you only get half of your DNA from your mother and half from your father, and they get only half from each of their parents, etc., it's possible that she could be American Indian but the DNA not come out in the test.
A much more accurate way of determining her heritage would be to do her family tree, which has been done by genealogists on both sides of the aisle. That's how they concluded that she was not Native American at all.
And they (again, on both sides of the aisle), were livid that she had lied.
No, I do not believe you are correct. A dna test would show down to 1% how many genes came from North America. This is how you see if you have Native American genes. My daughter has 17% Native American genes (probably taino).
If she doesn’t have even 1% of her genes from North America, it’s a pretty sure thing she doesn’t have Native American genes.