I'm sorry to say that there is no way to get it to return to it's earlier size and shape. The combination of the water and the agitation has changed the structure of the wool.
Seventy some years ago my mother washed my wool baby blanket. It shrunk to doll size. She saved it and I used it as a doll blanket for years. I loved the blanket knowing that it was once mine when I was a baby.
I washed a wool sweater several years ago. The label said it was hand washable but it shrunk anyway. The next spring I found the same sweater at The Rack at a very reduced price. That's the only way I know of "fixing" shrunk wool.
You can use the material in the skirt to make something else. You could felt the material which would shrink it more creating a different look all together. I have only read about felting material. I have seen felted hats, vests, and even a blazer that were beautiful. Felting compacts the fibers to produce a woven material that looks a lot like felt.
I have purchased washable wool in the last 10 years or so and stay away from clothes that cannot be washed because I'm not so careful about fabric care. The process for producing washable wool has become quite good.
The actual fibers shrink because the lanolin is washed off. I suppose you can replace the lanolin on the surface of the fibers but this will not lengthen them; only make them softer.
Because the lanolin is washed off of the fibers the fibers stick together. I know of no way to unstick them. The reason that we can block a knit fabric to a somewhat larger size is that we can stretch the knit. The main reason for blocking is to give the knitted fabric a specific shape. We are lining up the fibers and the fabric and are not actually changing fibers or stitches.
I did try to block my sweater. It blocked just fine only it was still a smaller size. I have heard of someone blocking a sweater and successfully adding perhaps an inch. In doing so the spaces between the stitches were marginally larger. I have never heard of anyone being able to change the size of woven fabric.