It's hard to tell exactly what it is. I have seen peck marks or injuries look a little discolored. Pox could be the problem, but it doesn't look that clear. The little mark on her comb tip could be a similar mark. If you have a heavy mosquito population right now, pox can certainly be a possiblity. Pox usually lasts about 3 weeks without complications, while a peck or wound will take a few weeks to heal.