I have read quite a bit on here but as I am a new chicken owner, I still really don't know what is wrong and could use some help. Ok... I worked past dark all last week and was not able to observe my flock of 6 hens all last week...I don't know if my hen showed any signs of sickness prior to Sunday. I did let the chickens free range on Saturday, and did not notice anything, but may have not looked closely...Well on Sunday I noticed a Leghorn just laying in the yard. I realized that she had a very pale, floppy comb. I picked her up and she has always been small but seemed to weigh nothing...I tried to offer her some feed which she ate a little, but not much and just wandered around away from the flock, moving slowly. I had to leave the house, and came back after dark and she had made it in the coop to the lowest roost pole. Monday Morning, left for work early just as the chickens were getting up. The hen just laid in the coop, I don't know if she ate or drank all day, and when I got home after dark, she was up on the highest roost in between her sisters, so I thought this was positive. Well after reading on here I knew that I needed to isolate her. This morning, Tuesday, I put her in a large plastic tote in the garage with pine shavings and food and water...I offered her yogurt, which she ate 1 bite, then refused. I figured at the very least she could rest more peacefully. When I got home this afternoon, early, it didn't look as if she ate or drank at all...I offered more water, got her to drink a tiny bit, then put her in the backyard with her sisters to see how she would do. I made her a scrambled egg, which she ate just a couple bites, then layed down almost falling asleep sitting up... Then I had to leave to take my dog to the vet and wasn't able to return till after dark. When I went to see if she made it in the coop, she had not, and was laying on the ground outside the coop asleep...I got her and put her in the tote in the garage for the night, offered her water (with apple cider vinegar), just held the dish up to her beak, and she actually drank more than I have seen her drink in 2 days, but still no food. Then she all of a sudden, stood up, puffed up really big, I left her alone for 5 mins, went back to check on her and offer her more water, and she was asleep standing up so I have left her alone. -Today I looked at her vent, and it seemed to look ok? -I felt for an egg, and I'm not sure if I could feel and egg or not... -She seems to be breathing fine, no wheezing. -I have never wormed my chickens -All the others are perfectly fine -They were eating some food that I think was old, it smelled bad, so I switched to fresh (Countryside Organics) food. Here is a picture of her with the eggs and her poop from today (she pooped twice (green) that I know of today and both looked the same). Any help would be very appreciated.