Isn't she Darling!
Open a large image, I usually work with a 500x500 size.
Drag or copy and paste your doll to the new image.
Close the original.
Using the magic lasso icon, trace around her legs as shown.
Click ON her legs to select them.
Add a new layer and drag under the floating section so the legs will be on it's own layer.
Click on the body layer and move it down over the legs as shown.