2 yr old buff orp not well

[Granny23]

I just finished a post about my 2 yr old buff orp and her self isolation from my other 5 hens in the behavior section. I just went out to get her to look at her and she was in the same cool spot in a dirt nest under a bush. Ive been finding her there most days after they are let out in the morning.
I picked her up and took her to their enclosure and set her down. She just stands there. Then she had a very watery stool. Picture below.Now she's standing there sleeping on both legs. The back of her comb looks a tiny bruised but other than that she is fully feathered and clean looking. Lately she hasnt been as hungry either. If I give the girls treats she wouldn't dive in and unless I gave her some separately she wouldn't get any. She is ok some days and not so ok others. I have NO clue how to help her.
Is there anything I can try?? My other 5 hens are fine.
I went back out about 10 mins later and she is still standing in the same spot where she pooped.

 

[ChickenFeeds]

I really don’t know. I’ve heard that chickens can isolate themselves from others because of sickness and pecking order, so it could be one of those, but I really don’t know. If it is the pecking order, that would also explain why she’s not eating treats. Pecking order would also explain why the back of her comb is bruised. Is she new or are there any new hens? Pecking order problems normally occur when there are new chickens or when chickens are young.

 

[Granny23]

I really don’t know. I’ve heard that chickens can isolate themselves from others because of sickness and pecking order, so it could be one of those, but I really don’t know. If it is the pecking order, that would also explain why she’s not eating treats. Pecking order would also explain why the back of her comb is bruised. Is she new or are there any new hens? Pecking order problems normally occur when there are new chickens or when chickens are young.

No new hens. I have 6 and she was one of the first 2. I just put her in a part of the coop that is close to the others but she is separate. She seems a little weak too...unsteady on her feet. She and the others have been together for 2 yrs with the newest pair being 8 mos.No problem at all until a couple weeks ago I noticed her isolating...but she was still eating. Tonight even alone she wouldn't eat a broken up piece of corn meal muffin.
My granddaughter who hand raised all our girls is convinced she's going to die.
Update: after it got dark I checked on her because I isolated her and she was laying by the door wanting in. She went up the ladder to the roost with the others.and stayed there. No problems with any of the other 5.