Based on the well documented and detailed information you’ve provided, the answer is no.
I was reading the whole thing thinking no, but that mtDNA would be the clincher, and then you had mtDNA results.
You’re missing some words in the mtDNA statement though, I was confused at first. I think you meant to say “been the daughter of Mary Butler “
I don’t see why the weak evidence she was indigenous would trump the mtDNA evidence for other researchers. It would only be stronger if you had multiple pieces of mtDNA evidence.