“I just don’t have the courage to tell the *girls* why”
I agree that you should NOT discuss any of these issues with children other than your own.
But, if there is a parent there (which I’d like to think there would be) perhaps you could share your feelings with them, in a low key way, of course.
I bet there are plenty of parents with girls in this program that have no idea what is going on.
But I’ll add this, when I left the girl scouts (40+ years ago) my wild Irish Grandmother shook my hand an congratulated me for “finally” leaving that dreadful “quasi-military” organization.