6 month old Dominique not walking

1) I have a 6 month old Dominique hen. She was a good weight and is now underweight. I had not noticed that she was under weight until she was not moving around the pen and I went to check on her.
2) She will waddle very low to the ground with her wings kind of hanging down. She is very alert, her waddles and combs are very bright red. She will just sit and stay there and look around. She is grooming herself and seems to be happy with the exception of not moving around.
3) I noticed that she was like this 3 days ago.
4) None of my other birds are exhibiting any systems of being sick or doing what she is doing. I have a flock of 14 other hens that she is with. They are all a little over a year old except for her, which is 6 months old.
5) I have checked her and cannot find any injuries on her. She does not seem to mind when I move her legs around. Her legs are not dry or scaly looking. I have not been able to see any mites or lice on her. She has not lost any feathers and is not molting. She does not have any bllod in her stool. I did notice that when I picked her up at first she seemed to have some feces stuck on her feathers around vent. The vent is not swollen, but does look a little bit irritated which I thought was due to the feces that was on her.

6) There is nothing that I know of that would have caused this to start.
7) I feed all of my hens a layer pellet or crumble, for the last few months it has been a crumble and this is down at all times. They are also let out of their coop each morning to free range and then get put up each night. I also give them fresh green cabbage that has been shredded up. They have water available to them at all times.
8) Her poop is on the runny side and is green and white.
9) 2 days ago I brought her into the house thinking that she might have been egg bound since she had started laying about a month ago. I did soak her in a warm epson salt bath, which she seemed to really like. I also did check by inserting my finger to check for an egg and there was not one. also after doing this she did poop which led me to believe that she in fact is not egg bound. She has pooped several more times since then.

I have given her some Nutri drench in her water and she has drank that. I also wormed all of the chickens the day that I found her like this with Wazzine. I started her on antibiotics yesterday.

She is currently in a large metal dog cage in the house. She has food and water (with antibiotics in it) in their with her. She seems to go to the water and food and eat and drink and then just stays there. I noticed 2 days ago that she was in the cage with her beak open and seemed to be breathing a little harder than normal, but she is not doing that right now. I cuaght some earthworms and she gobbled those up as fast as she could. I have been giving her bugs and worms along with her feed and some vegetables trying to get her to get some weight back on and to make sure she is eating enough.
10 ) I would like to treat her myself but I do not know what else to try.What is your intent as far as treatment? For example, do you want to treat completely yourself, or do you need help in stabilizing the bird til you can get to a vet?
11) I do not have a picture of her at this time but will post one of her.
12) In the barn where the chickens stay is dirt floor and pine shavings in the nesting box. Right now she is inside in a dog cage.