I'd consider giving her calcium too just in case she's having some troubles expelling an egg.
Ah, I see you've added you think she may have Ascites. Do you feel bloat/fluid in her abdomen below the vent between her legs? Is the abdomen tight like a drum?
Ascites can be due to reproductive problems and/or organ failure.
The excess fluid can cause the digestive system (crop/intestines) to slow due to inflammation and pressure.
Some folks drain the excess fluid to give some relief, that's up to you. A lot of times a hen can live for a long time afterward, it really depends on what's causing the symptom. Sometimes unfortunately, draining is not all that helpful.