I checked to see if I could see anything on her and I didn't. I did go out and spray down their coop yesterday though just in case. I'll have to watch and see over the next few days I guess.
Could be mites, lice, etc. they are hard to see sometime. Nighttime with a flashlight is your best opportunity. If it's picking/pecking you can put a saddle on her to limit access to that area. Also, with this heat make sure there is enough ventilation in the coop and shade in the run. I have a fan in my chicken house right now to help with the heat.