Injured, limping chicken

[VTChickies]

I noticed yesterday that one of the girls was standing on one leg like a flamingo, and when I got her to move she was limping pretty badly. I looked more closely and she had a sore with dried blood on the back of her left leg. Here is a picture of how it looks today. She is still limping around. Her comb has white speckles which I'm not sure whether or not that's normal.

I'm reluctant to separate her, because when I tried to separate a chicken that was being pecked, she threw an absolute fit and wanted to be with the flock. Letting them free range has fixed the pecking issue but now I think may have caused this injury. ANy advice on how to care for her would be greatly appreciated.

 

[Wyorp Rock]

Welcome to BYC!

It's hard to tell from the photo, is it a cut?
If you can separate her that would be a good idea. If you have a wire kennel that you can set up outside near the other chickens, she may stay calm. Put food and water in there for her.
If it is a cut, clean it well with soap and water or a diluted betadine solution, pat dry and apply some plain neosporin or vetericyn spray.
Keep an eye on the cut to make sure there is no infection, pus, bad odor, etc.