Ergh, people. They need to stfu seriously.
The mother of another student walked over and proceeded to tell me to control my child, that he was ruining everything and that I should just take him home or get him to be quiet. She finished by telling me that I was extremely rude for not allowing the staff to help, well my face must have said everything my mouth didn’t, cause she moved away rather quickly.
When a similar situation arises in future, remember that feeling. It should then channel that bitchface and should scare off all but the stupidest thus ensuring that you only have the kids to deal with and not anyone else's blatant ignorant stupidity.
With aforementioned rude sod I think you did a brilliant job restraining yourself, had it been me she wouldn't have made it past the first line.

Trust me, had I not been surrounded by children, including my own little ones as well she would have been the one sorry woman. I have in the past let my mouth run away when my anger has reached its tolerance for stupidity. Unfortunately this was just not he place for such language.