More after the break...
Some more promo and behind-the-scenes pictures:
This was at the Propstore for a bit:
I've heard some say the jacket given to her by Kaylee is reminiscent of the Turquoise Jacket Kaylee wears in Firefly's Pilot episode. It is not the same jacket (obviously), but I would bet that they were thinking on those lines.
Also, she also wears these boots with her Battle costume.
My Photobucket Album for River.
Serenifly Costumes site for River.