Probably don't need to say this, but don't go with them if you have to wait in a hot car. Kids Contact with kids should be supervised. Kids do unexpected things. Kids are NOT for herding. I still don't quite get this, and sometimes I have to stay inside when there are a lot of kids outside.
Kids have more status than dogs.
That might be hard to understand if the kid is acting like a puppy, and you are a grownup dog. They said they wanted to be there when she did it. I made sad doggie eyes at them all. We Corgis have a reputation for liking kids. You may need to catch up here, as I did.