Yet ANOTHER help me find a kid's book thread

I really want to find a book I read when I was young. It would have had to have been in the sixties because by the seventies I was in high school, and older than the target audience. I can remember a lot about the book EXCEPT for names, and the title. Grrr.

There’s a family living in the southwest US. Mom, Dad, older brother, slightly younger sister. They are Native Americans, I think, but am not sure, of Apache heritage. There’s an older(great) uncle whom I think is related to the father. Mom and Dad have an art studio, live pretty much as the average American does.

For what reasons I can’t remember the mother’s grandfather, whom she has had little contact with(he’s kind of been a recluse) must come to live with them for a while. This guy is ancient, and bemoans the loss of his people’s heritage.

To humor the old man the kids agree to take “lessons” from him. He teaches the girl how to do girl things, but focuses mostly on the boy, probably his only living male descendant. How to hunt, to ride, even puts him through a trial where he’s supposed to run way out into the desert with a mouthful of water, without stopping, and come back without swallowing the water. At one point the girl has a stint as an extra in a Western, because she and her brother helped build the native shelters. The old geezer sees the “village” being attacked by “U.S. Cavalry” and thinks it’s the real thing, and nearly shoots one of the actors to protect the girl. The film director is still so taken with his authenticity he hires the dude for a scene where some cattle are supposed to be stolen, and the old guy actually takes them, and butchers one for a feast with his great-grandson.

There are other things that happen, but is this enough to help? It irks me that with all I can remember I don’t remember any names at all.

Could it be Shaman’s Last Raid?

That’s it! I recognize the cover art as well. Thank you so much!