Chicken with respiratory sickness?

[The Chick Addict]

Is she pooping?

Yes she is, she's doing large, watery poops with some urates and green specks, they look like this:

I'd check her crop in the morning to see if its emptied. The liquid may be due to a crop problem which is not uncommon in hens that have reproductive disorders.

Okay, I'll do that tomorrow morning! Just felt it and it feels soft but not completely empty. Uh oh, how would I know if it's a reproductive issue? I just felt her abdomen and it's still slightly swollen though I drained all of the fluid... could that be an indicator? It doesn't feel hard at all, very soft.
The poor girl still isn't looking great and is pretty lethargic.

 

[Wyorp Rock]

Okay, I'll do that tomorrow morning! Just felt it and it feels soft but not completely empty. Uh oh, how would I know if it's a reproductive issue? I just felt her abdomen and it's still slightly swollen though I drained all of the fluid... could that be an indicator? It doesn't feel hard at all, very soft.
The poor girl still isn't looking great and is pretty lethargic.

Well, you drained fluid from the abdomen. A common cause of the Symptom Ascites (Water Belly) can be a reproductive disorder (EYP, Cancer, etc.) and/or organ dysfunction/failure. The only way to really know the cause of the fluid would be to investigate further if you lose her (have a necropsy performed).

Fluid can sometimes build back up quickly. Draining isn't a cure, the condition that is causing the fluid still exists. Draining is part of supportive care, sometimes its helps, but sometimes it doesn't.

I'd work on hydration, keep her relatively warm and encourage her to eat. Re-check her crop again for the next few mornings.