Thanks, all, for your comments and suggestions about the ruffles on Twirl. I agree. I didn't like it much, either. So I've taken the skirt apart, removed the ruffles, shortened the skirt 6 inches (it was WAY too long) and this is where I am now:
I had to redraw the ruffle circles, since shortening the skirt meant that I had to cut off that bottom tier. So now it's redrawn and remarked. I'm redoing the ruffles. See?
Just for the record, I'm using the gathering foot, set on 1, with a stitch length of 4. After some measuring, I found that this gives me a gathering ratio of 3 to 1. That's nice and full and fluffy, and I was right about it taking a ton of fabric for those cute little ruffles.
Here's a heads-on shot of the gathering foot in action. In these photos I'm actually gathering two ruffles at one time!
I love this presser foot. If one is available for your machine, get it. It's tons of fun.
Now I have the dress perfectly fitted to The Princess, with the correct finished length all figured out (finally!), and since I'm off tomorrow--yippee--I plan to cut out the REAL Twirl!