sounds like a combination of bad parenting on the part of the girl's mother and bad managing on the part of the manager. i know what i would have done if i had been you. i would have marched over and explained that my son was going to be physically sick and unless they wanted to be held legally liable they'd better move and then, knowing me, i would have made sure they moved. maybe not politically correct, but when it comes to my kid, all bets are off.