I'm not every experienced overall, so I encourage you to research the symptoms you're seeing with her. I have had the occasion to nurse a few back to health who were acting off for various reasons. Has she pooped? If nothing will go in and nothing is coming out, she's probably got an impacted crop - something is plugging up the works, so to speak.
Here's some advice from an old thread: You need to get some olive oil (or similar vegetable-based oil) down her, and gently massage her crop to break up the mass inside it. If she will willingly take the oil a little at a time, great, but if not, you need to drip it onto the top of her beak so that she is encouraged to swallow it once it runs down the side (don't ever try and force liquids down a chicken's beak - it is incredibly easy to drown them if it goes down the wrong tube). Once she's had a couple of mls of oil, you can start to gently knead the crop. Do not push hard upwards (this may cause her to regurgitate some of the contents and then breathe them into her respiratory system, and is another way of accidentally choking/drowning them.) Just get hold of the mass and gently try and mix it with the oil and soften it with your fingertips.
If you can, some organic apple cider vinegar may also be good for chemically breaking up any fibrous material in her crop, so if she'll take that too, all the better.
She MUST continue to take fluids - lack of food can be tolerated by their little bodies much longer than lack of water. Again, a dropper to put water put onto the top of the beak is a way of making her take it if she doesn't really want to. If you have some children's soluble vitamins you can put in the water, all the better.
If after a couple of days of massage (ten minutes every couple of hours should do it - not constantly, it'll stress her too much, even if she appears to enjoy it) she still has a full crop and is not improving, there is surgery... but let's not go there just yet.
