Pretend the kids aren't there, no moderation. There's no reason to be uncomfortable about kids showing up to an adult space, you do not have to accommodate them.

If the hyper Karen wants to make a moral panic then they're gonna try to make a moral panic with or without kids. Even in your example the kids are just a prop to do what they already were trying to do. Deal with the hyper Karen if you have a hyper Karen problem.