Tape her foot flat, and with toes in the correct positions, you may need to use a piece of cardboard under her foot. Don't use vetwrap or coban; you need something with adhesive that will hold them in place.
http://browneggblueegg.com/Article/CrookedFeet/CrookedFeet.html has a photo and instructions. Bandaid on top and bottom, cloth tape on top and bottom, duct tape on bottom and bandaid or cloth tape on top, etc. Even package tape will work. Just make sure that the "sole" of the shoe is not slippery. Oh I just saw this! Thanks so much. I'm going to try it with masking tape and see what happens. She actually walked better without the brace between her legs. I'm not sure if I did it right or if she just needs to adjust. Not sure how old the bird is...a week for a small chick, up to a couple of months for an older bird. Once they are mature I doubt that you can help.