Hi, Eddie. Since you tagged me, I'll put in my two cents. I have not had this issue in years, but I know after draining several hens repeatedly that the issue is not the fluid, but the underlying cause of the fluid. That is not going away. She has some reproductive or other issue, usually it's internal laying, that is causing the fluid to build up in her body, including her lungs. Draining only alleviates the pressure temporarily and stresses her out in and of itself.
I no longer drain hens. I've even had one or two bloat up and then, the fluid dissipate, but yours sounds like she is in the final stages. My thread on Olivia shows how much I drained that sweet little hen, but she was laying internally. In fact, I have a thread on a hen who was bloating for literally 3 years or her less than 4 years of life and all her yolks were being deposited into her liver, we found those postmortem, verified by a vet I consulted.
I know you care deeply about this hen as I did mine, but you should brace yourself for the inevitable here. I have not read all the posts, but at this point, I would make her a warm bed in low light(she should not have to fight the cold in her condition), give her warm food like scrambled eggs, fresh water with some apple cider vinegar with "the mother" (cuts phlegm and has vitamins and minerals) in it and let her rest. I've held many a hen as she passed away to comfort her. Sometimes, all you can do is care. She feels it, I believe that with all my heart. They do know.
Here are two threads of mine, two different hen's histories:
https://www.backyardchickens.com/threads/drained-a-hens-abdomen-rest-in-peace-olivia-11-5-10.362422/
https://www.backyardchickens.com/th...w-fluid-rip-hope-graphic-photos-added.924895/