I think you handled it really well. I don't usually say much because my experience is people don't really understand and I have no concise way to explain it to get my point across, and they get uncomfortable with the conversation and tune me out anyway. I'm in an awkward place at my 5 year old's gymnastics and sometimes in our home school group, when things get loud or crowded or people are unexpectedly touching her and all of a sudden she's either trying to escape or upset or acting strangely. Or a friend's house she keeps all of her windows covered so it's nothing but flouresent lighting and her kids have tons and tons of toys with batteries that are all really noisy. I don't want to give people the impression that I expect them to walk on eggshells with her, but I do sometimes wish I could help them understand.