Pemberley: Thanks for the update.
If I'm still on target with my understanding of what happened, I'd try to help your DD move on from this a little faster by pointing out that, while the boys might have gotten loud and angry, they weren't going to hurt her, so there's no need to be afraid.
Also, I'd be keen to point out that not all boys behave the same way, because you don't want to encourage stereotyping.
As for this:
"I almost laughed once but I suppressed it. After all I don't want to encourage that behavior do I?"
I'd give her permission to go ahead and laugh. It's not her responsibility to make sure the other kids behave. She can relax and enjoy being a kid.
And BTW... a "check" is common in half-court basketball, where both teams are going to the same basket. I think it's supposed to give the team that just scored a basket an opportunity to turn around and prepare to defend. After a basket is scored, the ball goes to the other team*, and one of their players takes it to midcourt, says, "Check!", and passes to a player on the now-defending team... who passes it back, and normal play resumes.
*Sometimes a game will be played with a modified rule of "winners bring in," where a team who scores gets to keep the ball, but the play still restarts the same, with the ball at midcourt and a check pass to the opponent.
