Drinking, NOT eating NoT laying!!!!

[Chicks and Hens]

My chicken is drinking a ton!!! But when I bring food out all the chickens come rushing but not Rex. Rex is my Black Sexlink she was laying eggs over the summer but now it is getting colder and she has STOPPED laying. What can I do ???

Also her Comb is a red purple colour and is leaning towards one side

 

[Chicks and Hens]

And she will stay in one spot for hours and is having a hard time running and flying

 

[lazy gardener]

check to see if she is egg bound. search the threads re: that topic. When was her last egg?

 

[Chicks and Hens]

about a week ago

 

[Chicks and Hens]

I put her to sleep tonight as i always do i close up the coop and i checked earlier tonight and she was sitting on the floor sleeping she wasnt up on the roost sleeping!! HELPPPP!!!!