How would you guys handle this?

Holly_1007

Apparently my SD thought it would be a great idea to strip naked in the library yesterday at school.

BM called DH and told him she got a call from the principal about it.  We have been reinforcing privacy for 6+ months now at our house.  Having her close her bedroom door when she gets changed etc. 

BM told us that SD thinks it is funny to run around their house naked, opens the bathroom door when people are using the bathroom etc.  BM is scared of being the bad guy, so she pretty much never yells at SD.

DH flipped out at BM because she has a ton of stuff planned for SD this summer, including a week long Vaca with her grandparents.  BM has been threatening to take away the vaca because of SD's behavior, but DH and I both know she won't actually cancel it.  DH called BM on it and BM just had one excuse after another. DH was finally like "Look, if you're not going to follow through on the punishment, then don't threaten to take it away!" She just doesn't get it. 

So I don't even know what SD's punishment is going to be at her mom's house, We have SD tomorrow for a few hours and then not again until next weekend, so DH and I aren't really sure how to punish her.  Next weekend is her birthday, so we have the water park planned, I'm not sure if we should cancel it? Postpone it?

I'm literally nauseous at the thought of my SD stripping naked in the library. I don't know what to do. Any input?