It was good that she was concerned enough to do something about it, how many of us would?!
But she he could have just asked if "everything was alright" and I can totally see that you would have just wanted to yell at her
I have a chld with SN but if I saw a struggle going on getting a child into a car it would probably cross my mind that the child might be being taken against their will
Not that I would have reacted like her!! I probably would have stood around nearby. But then again, that wouldn't be much help if child was being abducted lol
Having cards to give would be a great idea but as you say you have no free hands
we have signs on each side of our car windows saying "Remember, disabilities are not always visible"
Not that it might make any difference but you never know
Otherwise I would just turn round and say "My son has ......if you could just give us some space please"
sorry, have waffled!!!!!!!!!