As a service to my readers, I'm listing some online stores that are having Memorial Day sales of skorts that I think could be worn as practice skirts.
A skort is a skirt with built in shorts. Usually these are more 'generously fitted' than the skirts you buy from skate shops.
Title 9. Mainly a running, biking, outdoor sports store, Has a lot of variety and good quality skorts. I have a couple from them.
Team Estrogen: Mainly biking. Lots of skirts with shorts. Some are padded shorts for bike riding, double check before you order.
Terry Cycles, More biking skorts. I don't see a Memorial Day sale. I own a skort from them and I liked it. They seem to run a little longer than other places.
Now for some practice skirts without built in shorts. I recommend just wear some black booty shorts underneath these. If you want to be fancy, buy the skirt then find some dance pants in a matching color to wear underneath.
American Apparel. Look through the pictures of skirts and you'll see a bunch of shorter skirts that are just to die for, I have a cute double chiffon skirt from them. The short skirts run short, They are having a memorial day sale.
So in general these skirts and short are available is sizes that adult women might feel comfortable in. Some sites even have plus sizes. The Memorial Day sale at most of them is a great deal for the holiday.