If my parents had asked me to do that, I would have taken my sewing scissors to every skirt in the house and rendered them all un-wearable. Hopefully your girls won't go that far, but if you really want to communicate gender equality, you'll let them wear pants or skirts, depending on what they want.

I only wear skirts at Renaissance Faires and similar events. I gave my younger brother my utilikilt (http://www.utilikilts.com/), which is cool int eh summer without being restrictive.