They say here when you start worming your chickens for the first time to treat with Wazine in their water and do a more thorough worming later.
I'd keep hydrating her. You could add a quarter of plain crushed aspirin, a little bit of crushed tums or calcium supplement. I have some powdered gatorade at home. You could use a pinch of jello powder for taste (cherry or strawberry). I drip it on the top of the beak with a dripper and they'll 'sippy sip' especially if you're sweet talking them. In fact I'd encourage it because it'll encourage her to drink.
Try little bits of soft bread to eat.
Also something to think about, maybe she needs some antibiotic because of respiratory problems. Any other symptoms?
Mites and lice can kill. Did you say she had a pale comb because external parasites can cause this too. You could give her a nice flea bath. The last time I bathed one I used the Adams with Precor. It's a good time to do the 'sippy sip'.
BTW, chickens get internal parasites from the worms, snails, soil they digest. I doubt there's a chicken in the world that doesn't have them.
I guess in summary, external or internal parasites unless she has other symptoms (i.e., swollen abdomen, crop, sneezes).