You can treat her with antibiotics which can usually be found at your local feed store. If you have a vet that you use he/she may be able to recommend which one is most suitable for your situation.
While the antibiotics won't "cure" they may help provide some supportive care and give her some...
You can feed her normal poultry ration if she will eat it, some scrambled or hard boiled egg, tuna, etc. Whatever she will eat that is good nutritionally for her. If you have vitamins/electrolytes for poultry you can add that to her water if you want.
As far as the other hen's behavior, I don't...
Poor thing, she doesn't look well does she. She is a lovely girl.
My best guess would be Peritonitis - just looking at her stance and the symptoms that you describe.
Green poo can be an indication of infection or nutrition (she's not able to absorb nutrients or not eating enough because she...
Do you have any photos of her and the "swelling"?
What does her poo look like?
Does she stand at all?
Could be "internal laying", Peritonitis. If you were getting yellow liquid out, then it is most likely Peritonitis. (Ascites is usually associated with "water belly" and clear liquid being...