Fold over top of the skirt twice (1st by 1/2" and then by 1 1/8")and iron. Sew to form a channel for the elastic leaving an inch or so open. Insert elastic with a safety pin and pull through the channel. Try the skirt on your little one at this point to find a comfortable place to sew the elastic together (if it's not possible to try it on her sew the elastic so that it stretches to 12.5") and sew up the opening. Hem by folding each ruffle over twice to make a 1/4" hem.