Sick pullet, home remedies

One of my COVID-19 panic buying chickens is sick. Yesterday, she didn't want to eat dinner, which isn't that unusual. This morning I found her on the floor of the chicken coop. I thought she was dead at first but when I touched her, she began kicking her legs and opened her eyes before settling.

Signs

1. Lethargy
2. Empty crop
3. Dry oral mucosa (likely due to not drinking now for 15+ hours)
4. Reddish-brown smear on rear of leg. Bloody stool?
5. An area of likely very loose stool in a single spot in the coop (I cleaned it out and examined all the litter)
   
   yellow particles are chick crumble

Differential diagnosis: Coccidiosis?

This colonizing protozoa is extremely common. The pullet is about 10 weeks old now and has been in the coop and out of the brooder for 3 weeks. I thought this might be a little old to get coccidiosis but I suppose it is possible that she was exposed to a strain she wasn't exposed to before

Treatment

I isolated the pullet in the barn. I have been giving her syringes of water by wrapping her in a towel and holding her looking at me with her head slightly back. Tomorrow I am going to try a dewormer, Corid, in the water for all the chickens. I'll be surprised if this pullet survives based the extent of dehydration but hopefully that will help the other pullets.

I would appreciate any help, looking at you chicken experts like @goldenoakfarm.