Chicken not getting up!

[CutieBabyChicks]

Hi everyone! So I have a problem with our 3 month-ish old Polish. She's always been the weakest. We found her this morning in a corner, far away from the flock, covered in dust (might have been our 5-year-old who seperated her from the others :/ ). Since then, she hasn't been getting up, her mouth has been open, she seems like she might be limping a little bit, but at others times not really. She's been eating, but not really drinking. We brought her inside to care for her better. What should we do? Is this an injury, disease, etc?

Thanks!

EDIT: She hasn't been pooping, but she just did (pic below). Also, she has been yelping.

 

[azygous]

Poop doesn't appear abnormal. If your chicken isn't drinking , you need to give her fluids with an oral syringe. Warm sugar water would be best to begin with. The water you show in the photo, is that electrolytes in it? Try the sugar water first (warm water) then if she improves, give her a shot of electrolytes.

To safely administer fluids by oral syringe, slide the syringe into the right side of her beak (her right, not yours) slip it under the side of the tongue, and it will enter the esophagus, neatly avoiding the airway in the center of the throat.