Upside down hen

Came home from work today to find Florence on her back with her legs up. She had laid an egg and pooped in that position. Her rooster was standing on her and when I shooed him off she did not move anything except her head. She is alert and has bright clear eyes. She was fine last night before bed. I have soaked her and dried herand she is now seperated so she can have some peace. I'm guessing vitamin deficiency and or calcium defeciency since they live in my laundry room for now and get mostly game bird feed (that is what the breeder they came from was feeding). Actually hoping for that as opposed to disease. She is a new mom and had just recently started laying again. Before her bath she did not try to use her legs or wings at all. Now she will occasionally push with her legs and stretch out her wings. It looks like she may be trying to get up but she just scoots backward. It is getting steadier. I read that I could give baby vitamins without iron but no place in my little town had any. I did find baby vitamin d drops and have given her that as well as some egg. I was worried about b vitamins as well from things that I had read but again small town stores don't stock much. Couldn't even find brewers yeast or liver. I crushed up some pelleted food that our turtle has after looking over the vitamin content and mixed that with some egg yolk. She gobbled it up. Turtles have similar issues with what you can't give them. I'm planning to leave her in this little box so she isn't too far from her food and hope for the best till I can get home tomorrow. The only other odd thing I noticed is that her tail is down but seems to raise and lower with every breath - almost like she's tapping it. Her poops look normal. I do have safeguard but am reluctant to give her a wormer if her body is fighting something else. Also have roosterbooster wormer. Advice is welcome.

The game bird feed is probably good as long as it contains at least 16-20 % protein (some have 24% which is fine.) Was she vaccinated for Mareks disease? I would be a little concerned about something neurological like Mareks, but dehydration and vitamin deficiency can have similar effects. Does your feed store have poultry vitamins? Human B complex can be good, but Poultry Nutridrench, Poultry Cell, and other grands of poultry vitamins contain what she needs. Signs of Mareks can include weakness or paralysis in one or both legs or wings, or in the neck.

Our farm store doesn't have any. I bought her as a year old hen but I'm fairly sure she wasn't vaccinated. If she's still hanging on by the time I get home from work tomorrow I will see if the next town over has some poultry vitamins. Thanks.

Let us know how she does. State vets can do a necropsy on refrigerated bodies to look for causes of death. If you lose her, I would call them and keep the body refrigerated, to ship it to the dept of agriculture in your state. Here is a good link about this: http://www.metzerfarms.com/PoultryLabs.cfm

Some good links to read about Mareks disease:
https://extension.unh.edu/resources/files/Resource000791_Rep813.pdf
https://www.backyardchickens.com/a/the-great-big-giant-mareks-disease-faq