this skirt project, doesn't fray, so I wouldn't need to make a tiny hem. I measured the doll from waist to ankle and cut out a circle of fabric. I suspect I didn't allow enough for the seam when I added the bodice because the skirt was much too short. Hmm. Luckily I put it aside because a bit later I had a brainwave - I could just add another layer of skirt rather than starting all over again. That worked fine, hooray, fairy doll is fully clothed again.
By the way, I was rather rude about the pink fabric in my original post, but it turns out that the skirt is one of my favourites and I've worn it a lot!