I'm not attempting to be humorous or offensive in any way, and I suspect you've already considered it, but . . . My wife also has very small feet and has been known to find sneakers among the girls offerings. I have no idea whether there is the same sort of overlap between boys and men's sizes, nor do I know if any suitable shoes might be produced in Boys styles. If so, perhaps Brooks might have something. Beyond that, I can think of nothing else in RTW.
I know if I were in your situation, I wouldn't hesitate to consider this option.