I'm not an expert. The pale comb can be a sign of anemia.
the first things I'd try to rule out are:
1. Parasites.
Look for evidence of lice and mites. They can suck the life out of a chicken.
Visually inspect her poop
Bloody? Foamy? Off color? Worse stink than well, chicken poop?
Coccidiosis is usually bloody.
An system full of worms can be terrible too.
Most vets will run a stool sample to check for worms even if they don't treat chickens. Costs less than $20. (Except mine-who wants nothing to do with them)
Then come back to these forums and the experts will tell you how to treat them.
How is she walking?
An egg bound hen sometimes " walks like a penguin"
An internal exam is easy.
Glove up.
Lube up.
Be gentle! Don't root around like you're looking for parking meter money.
Don't break anything.
If you think there's an egg in there you can soak her in the sink with 1or 2 generous handfuls of Epsom salts and nice, very warm water.
10-15 minutes.
Pull up a stool.
She might fuss but in a minute when she realizes you aren't trying to drown her she'll most likely enjoy it.
You can put some lubrication inside her vent area if needed to facilitate the egg sliding out, but generally a good soak makes it unnecessary.
Towel dry. Blow dry with hairdryer if needed. Don't put her out in the cold soaking wet.
And lastly. Make sure if you're feeding pumpkins to chickens this time of year, they have access to plenty of grit so their gizzards can grind the shells.
Hoping somebody smart comes along soon to help because those are the only big ones I can think of!