I have really wide sit bones too, and there are almost no saddles out there really wide enough so I don't ride on the edges of the saddles with my bones! ....and I'm not even that big a woman!- just really wide pelvis I guess.

If it makes you feel any better- it seems that Bontrager saddles are not usually well liked by most women on TE here, -although there are a few women who do like them.