The problem is, I'm a short-tort of a Lolita, just barely coming in at 5'2" on a good day, and the dress hem hits well below my knees by about 1 1/2 - 2 1/2 inches. Because the skirt is so full, I can get away with huge levels of poof though, and I plan on doing just that. How much lift upwards could I get out of a good-sized petticoat? Go poof-wild. The skirt on this thing is huge. Here's a link to a picture with the JSK, not even fully spread either.
http://i33.photobucket.com/albums/d60/shattaga/2011-09-13_14-10-09_767.jpg