No, children don’t have to eat! lol
I don’t have children but I think I can translate what I’ve done to your issue. There always seemed to be a friend’s birthday party to go to as well. My puppy always seems to have some type of medical emergency when I least expect. Last year alone she caused a $250 bill for stealing raisins and eating them (poisonous to dogs), $400 bill for that time we had no idea she was allergic to a vaccine and almost DIED, and $100 for simply just being constipated. I loved her and hated her all 2016.
Anyway, I took these unexpected things and just started to expect them and make small funds for them. $10 a pay goes into the doggy fund, $10 a pay goes to the happy hour/party fund. It allowed me to stay on budget and when these things came up I was taking it out of the small funds rather than my emergency fund.
I hope this makes sense!