I hate to be the bearer of bad news, but I have been in a similar situation with a young pullet and things didn't end well. I bought her and a few other pullets at a trade-day type thing. When I got her, I didn't notice any type of sickness, but when she got to our house, things went south. She wouldn't eat or drink unless we hand fed her or put the water where she could reach it. She would either stay on the roost or outside in one place, depending on where my other hens chased her. She wouldn't do anything but sit or stand, and her eyes stayed closed. Eventually we noticed that she was having trouble breathing, and I began to think the poor thing was actually blind, or close to it. Turns out she had a respiratory illness (kind of like a human cold) and she had worms that had gotten behind her eyes which made it difficult for her to see. I can't remember the actual scientific terms for it, sorry. Long story short, my whole flock of 16 birds had to be thinned to 8 because she gave them a respiratory illness, and some of them just didn't get better even after antibiotics. We were having to medicate their water and put antibiotic cream on some of the hens. At one point I thought my best layer wasn't gonna make it. She was in pitiful shape and her eye was swollen up the size of a grape. In the end, we had to start disposing of the sick hens, the young pullet included. It was getting just too expensive buying medicine that just didn't seem to be working. When one would get better, then a few more would get sick. I'm not saying that is what is going on in your situation, just letting you know of my experience. I told myself I would never get chickens from that place again, and only from my family's trusted friend. My suggestion would be to get some antibiotics and see if she gets better. I do wish you the best of luck with your hen.
