Things that cause such symptoms are heat sickness and dehydration, toxin poisoning, coccidiosis, and Marek's. All are life threatening.
With a bit more information,we might be able to help you narrow it down and maybe to one that is treatable.
Location. Please tell us where you live. Add it to your profile so people don't need to keep asking. This tells us if you have been having weather conducive to heat sickness and coccidiosis or if you have an avian disease in your area.
Tell us your hen's habits and what she is fed. Have you checked to see if her feed has gotten wet and has gone moldy. Has she been vaccinated for Marek's?
Does your flock free-range? Access to a compost pile where spoiled food is tossed?
Any recent use of rodent poison or insecticides? Any yard machines in the chicken's yard that leak fluids onto the soil? Has anyone tossed out solvants onto the soil lately such as thinner, or coolants?
Have you imported any topsoil? Used any garden tools that are borrowed?
I live in Egypt, vaccination isn't available here for pet chickens, only available for certified farms, so she isn't, but I don't think her symptoms matxhes with merek's. Not sure though, is there anything I need to watch out for?
Nope, no poision was placed next to them, no machines in the yard, nope no solvents were thrown near them. They have pigeons living next to them though, can they affect each other? The pigeons are healthy though ):
no, didn't borrow any tools, no changes were made in the yard.
My chicken has a broken beak (I posted about her a lot of times, you can check my thread history to learn more about her and stuff) I hand feed her, sometimes she eats mashed food, her diet is based on fruits and vegetables, since the local feed isn't really a viable around so we home make it.
She was completely normal yesterday, no signs of sickness. I think she had some deficiency ): I can't put my hands on what is causing it though and it's confusing even though her diet is pretty diverse. I feed her three times a day.
She was dizzy this morning, losing coordination, couldn't walk straight, she's just laying down now. Still breathing, but weak heart break, really weak. Body contracting (looks like a sign of death )): ) her neck also keeps moving around in a circle? Then rests back, then forward. She keeps closing her eyes but I try to keep her awake. I'm giving her right now some electrolytes, I don't want to give vitamins again so I don't overwhelm her. I gave her garlic as an antioxidant. Didn't know what commercial one is suitable for chickens so I went with garlic as a safer option, since it's more natural, but it's slow ): I know that. Do I mix eggs with water and give her? Or is it going to be too much with the vitamins I gave her? I also gave her a vitamin mix and another dose of vitamin E. It looks like that's what she's lacking?
): Any advice is appreciated, she's really one of my lovable chickens and she has been a fighter all her life despite her disability.