I'm very sorry, it sounds like she's failing. I would try to give her fluids every 20 minutes, as much as you are able to get her to take. If you have electrolites then alternate electrolite water with plain fresh water. If she's dehydrated then that will take down her quickly. Use the method I gave you before, dripping it down the crease of your finger to the tip of the beak. It may take some time, but hopefully getting her warm and hydrated will help. I often carry chicks like this in a neckerchief around my neck held against my upper chest, kind of a little hammock, between giving them fluids. They can feel you and hear you and sometimes it gives them a will to live. I talk to them and hum, as I go about my day. That is what I would do now, see if the fluids help, that i more important than feed for now. Were you able to get any nutri drench in her?