I made it in a slightly stretchy fabric I picked up a spotlight (no idea what it is...). You can't really see it here but in amongst the lines is actually a flowery pattern - quite subtle but a bit of a change from the usual fairies and princess ballerinas.
I think you could make this in a normal non-stretch woven easily - it is reasonably generous and the waist is elasticated anyway. I chose to make the stand alone skirt (you can make one with inbuilt shorts but they seemed a bit pointless). The "bubble" is created by a difference between the lining and outer skirts. The outer is longer, and is looped up underneath to meet the lining, then a thin elastic sewn into the seam. I like it and Issy seems to find it comfy. The only real change I made was to bring the waist up (it's kind of a drop waist thing) as she tends to push it down under her tummy which would make it too long.
As you can see, she liked it :)