Uh, not exactly :) The default boots in Poser are conformable figures, you just select them (any part) and go to Figure/Conform to and conform them to your character. Make sure you choose the correct figure though or the results will be freaky! However, the skin will still show through in places. Usually by making the feet and toes invisible and a slight tapering of the shins(0.1)they should be all right. Now, for custom characters whose shin and thigh scalings have been changed it won't work that well. You will either have to scale everything back to 100% or use boots that are props not figures. Props you have to parent as they don't conform and might not stay exactly in place during animations. Conformable figures are supposed to be better for things like that. In your image it looks like you're using default Posette so conforming the boots on her shouldn't cause any problems.