Has she ever met any other native americans? If not, how do you know it was because of the fact that she is? It could very well just be her scent, or her voice, or a number of things... not her skin color. Remember that dogs *are* color-blind, so skin color isn't going to be as noticable as scent is.
My BC isn't racist at all. He dislikes random people of any race equally

mostly based on their voices & how they move. He typically likes my friends that are funny, laid back & friendly people and that pay attention to him... he loves all of black friends. He really despises my friend Christine, she is half Mexican, but the reason he doesn't like her (at least I think) is because she's kind of awkward & jumpy and has a whiney voice.
Fozzie just loves everyone

I'm sure he will start to show his preferences in a couple months, though.