holy cow. i sent a message to my nearest dna match. she is adopted.

[wnylib]

43. If your cousin is a direct line

descendant of a Native woman, no Native ancestry will show up in his male Y DNA or his female mtDNA. Only a straight line of female descendants of the Native woman in each genereration would carry a Native American mtDNA haplotype.

But, Native American genetic traits might show up in autosomal DNA (the DNA that you get from both parents) if the Native ancestry is not farther back than 5 or 6 generations. Some companies claim to go back 8 generations. However, it depends also on the genetic roll of the dice when chromosomes pair up at conception. There can be Native ancestry that doesn't show up in DNA if the genetic traces got dropped over generations of non Native ancestors. My aunt who looked 100% European is an example. Both my paternal grandparents had a mix of Native and European ancestry. But my aunt apparently inherited only the European traits from each parent. The aunt who looked 100% Native apparently inherited most of her DNA from the Native side of each parent. The rest of my aunts and uncles inherited mixed genetic traits.

So, comparing two cousins of mixed ancestry, for example, one cousin's DNA might show genetic traces of Native ancestry while the other one shows none. But they both have the same ancestors from the parents who are siblings.