Why are you driving him to school?

I have a 5th grade daughter who is a patrol and she's sometimes nervous about helping the little kids at carpool because there are so many rules about how you're not allowed to touch other kids. Today she and a friend thought a little kid with a gigantic backpack was cute and had an inside joke moment about it and the mom of that kid flipped out. My daughter got scolded and came home in tears. What should I do?

See how that works?

I would have sworn that this woman gave me a smirk at recess the other day.