I don't think her gender or any other marketing ploy would succeed at selling her work to the extent that it has sold if she didn't have talent. And I really don't see how her gender plays into it either- her anatomical configuration has nothing to do with her photographic ability, which was obviously extraordinary.
That's an interesting point, moving away from the Maier thing, in relation to Cindy Sherman, whose work plays on classic female stereotypes - often narcissistic stereotypes. The success of her work does actually depend on her gender and our ideas about narcissism. I think narcissism can very often be a means to communicate in photography, without the work actually being narcissistic. But that's conceptual photography for you!
'Cows are very fond of being photographed, and, unlike architecture, don't move.' - Oscar Wilde