Pale comb, losing feathers: normal?

If you feel she is ill you could quarantine her but she looks like she is molting from the photo. She may not lay through winter. Some breeds may lay a few eggs in winter and some may not dependant on age, breed, and daylight hours. Requires 14 hours of daylight to stimulate hormone that stimulates egg production. Just make sure you don’t see any lice or mites. You can provide higher protein feed and or treats occasionally to assist the molt so not as hard on the bird temporarily till new feathers in. Helps bring new feathers and winter down in faster. Just don’t make treats more than 10% of total diet. I make mealworm high protein seed cakes for mine and give occasionally throughout the week. I do not give treats everyday to my chickens so I don’t dilute their nutrition.

 

Looks like she is molting to me. Each bird molts in his/her own good time so you will not have all birds molting at the same time. Usually birds will molt around the age of 16-18months of age.
I would make sure she is eating/drinking, you can also give extra protein to help her through the molt. Sometimes they don't feel very well at this time, they can be standoffish, act a bit odd (don't like to be touched).
No need to quarantine her
https://the-chicken-chick.com/molting-what-is-it-and-how-to-help/

 

She does seem to be molting. Echo the suggestion to boost protein, and maybe put vitamins in the water. I would not treat with Corrid, just some extra protein and vitamins/electrolytes, maybe probiotics.