I saw Audrey Hepburn play a Native American in a film, I think it was called Unforgiven. Burt Lancaster, Lillian Gish and Audie Murphy were in it.
You are thinking of THE SEARCHERS. John Wayne went looking for his niece played by Natalie Wood who was abducted years before by Indians.
https://en.wikipedia.org/wiki/The_Searchers
The Unforgiven . Great movie .
STRANGE FILM. THE MYSTERIOUS THREATENING CHARACTER WHO KNOWS “THE SECRET” IS PLAYED BY JOSEPH WISEMANN BEST KNOWN FOR PLAYING DR. NO.