
I'm guessing you are the other half of "singlespeedstu" on STW, where I've just posted the following:
'The Pearl Izumi shoes are positively boat-like for any given size. Specialized are usually half a size down on your usual size, and they go up to a 42 (so equiv. 41).
I don't think she'll find women's Sidis that large but she could try the standard men's version; I have one pair each of men's and women's Dominators in a 40 and there's very little difference in the fit, apart from a slightly larger toe box in the men's.'
Hope that helps :o)