Thanks for responding. She does seem to have a minor impaction. Whatever made her start breathing hard and turning purple, I have no idea. She is back to normal color now, but she does have a small wheeze. It's hard to hear unless you hold your ear right next to her beak.
I don't know about sour crop. I gave her a little bit (she didn't let me give her more) of baking soda/water according to a recipe I found on here to flush her crop. I think it's working, but she keeps swallowing whatever comes up. I also gave her some olive oil to loosen the stuff in her crop up. Other than that, she is bright and looking around and whining to go back to the coop. She is isolated, we may bring her into the house to watch her better. We don't have access to a vet.
I don't think that she's egg-bound. We had a hen die from egg-binding not too long ago. This hen is not displaying any of the symptoms; if anything, I would say that her behavior, although unexpected since she hasn't been laying, was normal for her when she wants to lay. She often takes long breaks in laying, although this was the longest. She sometimes is agitated a day or two before she actually starts laying again.
I have been checking her crop lately; she has a large crop which she has had since we got her as a grown hen. It has never caused problems before, but I've been feeling it to make sure she is digesting. I just noticed this problem this morning, partially because our AMAZING rooster was standing over her. He alerted me by doing that.
Also, she is a bit overweight for a chicken, I think. Although, I'm not sure because I'm no expert on these things. She has more fat and has never liked to jump up or down very much on perches. This year she has been doing this more, but she has always been large.
