I really don't think it is as cut and dry of a situation as many want to make it out to be. I mean she was adopted by the Piapot in the 60s and I guess it comes down to how much do you believe of her saying she never saw her birth certificate as it had been destroyed in a fire etc.
The thing is, it is not only her but the first nation in questions that says she is one of them and in this case who are we, as non-natives, to tell them she is not.The thing is-she had previously claimed it via birth and not via loyalty and support. Example--years ago I went through with a ceremony with the We Wai Kum First Nation as an honoured friend. This does not make me a first nations person.
The problem is her position for 60+ years as been she was born in Saskatchewan and adopted by a US family, She got a Canadian passport in the 50's based upon this idea.