I'm sorry no one has replied to you sooner...unfortunately that happens a lot around here...
It seems pretty obvious to me that she probably is egg-bound: that is, an egg has either broken inside of her and the shell and debris is hurting her insides, or an unbroken egg is too big for her to pass, and other eggs are trying to form as well.
If you have a vet who will treat poultry, take her in as soon as possible! At this point it sounds like her condition is very serious.
If not (or while you're waiting for an appointment to open up), there are a few things you can try to do.
1) Check her vent. If there is any softened shell (it will look and feel rubbery and be roughly the same color as her eggs), try to gently pull it out. This has happened twice with two of my hens and has been the obstruction that made them egg-bound. Once I removed it, they were able to recover. If there is something red and fleshy, DON'T pull it out: that would be her oviduct, and it should be gently pushed back inside, and cold water gently squirted up her vent to encourage her muscles to contract and keep the oviduct inside.
2) Allow her belly to soak in a warm bath, and during the bath, gently stroke her abdomen, working from the front back to the vent. This can encourage the passage of the egg or any debris.
3) From the look of her poop, it seems that you should NOT give her any food at this point. My two hens who had poop like that were unable to pass the bulk of the food they ingested. Giving a hen more food while she's in this condition will only cause the food to build up in her system...which will be harmful!
4) Continue giving her vitamin water, and make sure she is in a warm (not hot), stress-free environment.
I certainly hope she improves. I'm so sorry no one responded to you...I have had that happen to me a handful of times and it has been very frustrating!
~Gresh~