No, I mean "allied" in the sense that Warren can be counted on to back legislation that protects the rights of Native Americans. As such, she is currently in the political minority in the Senate, so I think that that ought to count for something in the eyes of Cherokee leaders. They made a serious mistake in going after her for this, because they are weakening the coalition of support that they need. Do any of them not understand the significance of the fight that the Senate just had over the Kavanaugh confirmation and what that means for Native American rights? This is a political battle, and they need to stand by those who stand by them.
And I am offended because I am an American, and have a stake in how we as an imperial power treat the nations we once subjected to genocide and now claim plenary rights over as subject peoples. Everyone should care about this, not just those who happen to share blood with one of those tribes. That mentality, that whites should only care about white issues, is exactly what led to those previous atrocities, and it will be the destruction of the American empire unless it changes, eventually.
What are you talking about? I am an American, too, and I am offended by your suggestion that Warren did something here that ought to offend Cherokees. Warren's DNA test has nothing to do with historical genocide by the US federal government. It is about the President of the United States taunting a sitting US senator with racist smears because she once claimed to have Native American ancestors. As far as I know, Warren was never complicit in distributing blankets tainted with smallpox. At worst, she believed stories that her family told her about a Cherokee ancestor. What is the big deal here?