Button Quail hen...swollen face/eye on one side

[Big Button]

Please help! I have just come back from vacation (I had someone taking care of my birds while I was away) and I come back to one of my hens who now has a very swollen side of her face. Only one side. I took a picture of both sides so you can see the difference. I have seen her make this weird kind of sneeze where she shook her head and exhaled through her nose. I put a few drops of Vetericyn eye wash on her eye to hopefully help ease her discomfort. What do you think her problem is? Thank you so much!


Her history: I bought two hens from a pet store a few years ago. (never doing that again, they must have been inbred or something because they have feathers that never grow back) All my other buttons don't have issues like these two hens do. The other hen I bought has a crooked beak so I have to mix her food every morning with water just so she can eat. Poor things.

 

[JaeG]

Perhaps one of the other birds pecked her? @DK newbie might have some idea what's going on.