Urban Dreamer, I'm so sorry this happened. This same type of thing happened to a friend of mine recently. I'd sold her some pullets, and after she had them a couple of weeks, one of them couldn't get up at all one morning, and just sat in the bottom of the coop. We were afraid it was Mareks disease, but wanted to give her a chance. She moved her to a closet by herself in case it was Mareks, but brought her food and water a few times a day. It was over a week before she started trying to get up, but she did start trying, and after another week or so, is back to 100%. I guess she got her leg caught or fell?...or both? I don't know, but if you do have a vet close by, it would be a good idea for him to look at her. I hope it all turns out well for you as it did for my friend.
Welcome 829! I'm in South Central AR.