Morrigan has an upcoming project for which the kids pick a historical character and represent said character in a "Wax Museum." She chose Deborah Sampson, of whom I had never heard, but she was a woman who impersonated a man in order to fight in the American Revolution. So I think great! I am sure there are costumes online for this and promptly find an appropriate rig:
I show it to Morrigan who deadpans, "That's a boy." I tried to explain that she was going to be someone who pretended to be a boy in order to fight because girls couldn't. To which she said, "Why can't I just dress like a girl?" Hmmm, can we say missing the point?