You should have spoken out, Mrs. Bucket, but I understand your reasons for not doing so. This young woman is studying to become a professional, and someone needs to tell her that such patronizing treatment of her patients will result in a failed practice!
I understand the motivations for not speaking out in this situation, but to be frank, I think they're silly. To relay what a deafblind woman I completely adore expressed, we are (and we put ourselves under) the expectations of either dealing with the public treating us like children and asking invasive questions, or being 'angry disabled people' that don't live up to their 'responsibility to educate' the public.
If being an angry disabled person is the reason why people don't get away with patting me on the head or marveling on how I really did walk down the hall all by myself.. I vote being an angry disabled person.
Seriously, you just can't take things like that. It's not your responsibility to educate her, but it is your responsibility to expect people to treat you with whatever respect they'd have for you if you were able-bodied.