Welcome to BYC.
That is a good start, what you are doing, but she is already seriously ill if she is not eating. You must get her to eat. It is possible to tube feed her with a piece of aquarium hose, and a bulb or syringe. you pry her beak open and carefully thread the hose down her throat (the big hole) til it stops, or measure about how far down you need to thread it to get to her crop. You can fill her crop through the tube, make a mix of something like applesauce and yogurt, or put some cooked oatmeal in and thin it, or whatever you have. Make like a gruel. and feed it slowly, through the tube. This is no big deal, it sounds awful, but it's pretty easy to do. You can get some food and liquid into her that way. If you're nervous about it you don't have to necessarily be concerned about filling her crop all the way, as long as she gets some. She might have coccidiosis, which can be cured, if you have some Amprol you can mix that in what you are force feeding her. Amprol is what we like to use although there are other meds for coccidiosis and several are carried by feed stores. You can always get medicated chick starter, it has amprol in it, crush it, mix it in the gruel, and try that. Does she have any diarhea? That can be a symptom of cocci, but is not necessarily. Amprol is pretty gentle and will not hurt her, even it is not cocci, but something else.
Also look for signs of lice or mites. Parasites can kill an animal, and you might not notice them at first. Watch the rest of the flock for symptoms, too.
