Attached Link: http://www.poserfashion.net

First off, go to Serge Marck's site and read his excellent tutorial on clothes. I think the link is in the R'osity tutorials.

PoserFashion.net

Second, dynamics only work if you animate them. The fabric doesn't drape in frame one. And if you want the flow of cloth responding to her movement, she has to actually move. Easy solution: drape her/cloth her in the zero'd out position (the modified Da Vinci, which you get from a button on the joint editor). Then skip forward ten frames and pose her. When you animate the ten frames, the cloth will conform to the move to the pose.

This is the fast and dirty explanation. Take the time to read Serge Marck's tutorials (and pick up some great clothes while you're there).