One thing I can think of doing — though it would take some determined organization and would have some high risks — would be for several of the girls (with their parents involvement) conspire to cry SEXUAL ASSAULT against one of the creepy little locker-room invading “transgender” BOYS.
But they would have to WITNESS the assault, and make sure no non-conspirators were present, and they would have to STICK TO THEIR STORY.
The downside is the parents would be coaching their kids to lie, but such a lie might be justified — even in the mouths of children — in a culture battle to save society from these MONSTERS and the liberals who manufacture them.
If it was done correctly, and done three or four times in various jurisdiction, I believe it would be a powerful weapon to put a stop to this INSTITUTIONAL INSANITY.
I empathize with your intent, but bearing false witness is not a good habit to get kids started on.