So, if you want to sew it too, here is what you´re going to do:
The skirt has 3 layers - two from muslin and one from another fabric. I guess if your main fabric is not so transparent like mine was you can do it without this third layer. But you definitly have to go with two layers of muslin, it looks much nicer than just one. You will need 4 pieces of muslin fabric 40x30 inches and 2 pieces of another, non-transparent fabric, also 40x30 inches.
I must admit, here in Europe is much simpler (and cheaper) to buy this amount of fabric ´cause the width of fabrics in our stores is between 135 and 150 cm ( wich is cca 54-60 inches).
And you will also need some lastik band, mine was 20 inches long.
Cut the corners like in a picture above.
Take all 6 layers together, mark it with pins and sew it at the top.
Sew lastik band to get the circle.
Adjust your machine to a strait stitch, in the longest stitch length available. Sew two parallel lines down the side of your strip, leaving long threads at the ends. Then take the bottom (bobbin) threads and pull them with one hand, while gently pushing your fabric away from them with the other hand. Now you have to arrange your gathers so that they are even and that they fits your hips.
Sew lastik band to skirt.
And enjoy your spring walk..