It's pretty vague. I think it's been confirmed that she does some genuine supernatural stuff, like communicate with spirits or even magic like in OP.
I always assumed she was supposed to be like a Native American shaman, or something like that, but according to this >>85925234
she may or may not even be human. Also according to that post, her name is no longer "Buffalo Wing" but "BW". That was changed because it triggered white people, so it is possible that the mystery of her species is also a means to avoid triggering. Even though she is clearly meant to be a Native American, maybe they think they can just say that she isn't even human and avoid people looking for Native American stereotypes?