Do you know IF she injured the wing?
Have you innocluated your birds for paratyphoid?
Can you post a picture of the wing area?
Please isolate her.
If it is paratyphoid, you can treat with Baytril or the acquivelent. Be sure to inncoluate all your healthy birds Also, be sure to close any openings to your coop larger then 1/4 inch, and clean up all their food each night. Rats and roaches can bring on this type of disease.