Interesting because it's not something I've seen a lot of discussion about in terms of westerns, and that as one person's take on it, it throws up various questions, like your own about Maureen O'Hara. Or indeed are Son of Paleface, Annie Get Your Gun 'real' westerns?
Due to the nature of the films, women's roles have tended to be underwritten, and even when not, mainly ignored. I remember going to see Unforgiven, and while one could feel that it was a valiant attempt at reinvigorating the western, the women's roles, were basically as commodities.