One of my pullets has not gained as much weight as the others, and not eating as much. Last night, I let the little girls out with the big girls and then at lockup, I couldn't find her. I looked up and I saw an owl in the trees and so I thought maybe she had been taken by the owl. It was too dark to find her in the yard. This morning I went out to check to see if she had just been hiding, and I saw that she was in the coop. She must have just been hiding somewhere in the back. But she looked really sick, her feathers didn't look right and she was just letting the others step on her. So I pulled her out and that's when I noticed her breathing; she sounds really rough and she's got a rattle when she breathes. She's also really lethargic and her crop seems large. I have her in the small bathroom where I raised the baby chicks right now. She's in a small dog crate with the door open with lots of bedding and I also gave her some yogurt mixed with a little bit of the grower feed. I also have some leftover chick boost that I mixed up, and she's been drinking that and eating a little bit of the yogurt. She perks up a little when I'm offering her food or water, but then she thinks back down and appears to go to sleep. I'm afraid she may not make it through the night.