Likely, she's contagious to other fowl. I would treat her as such to be sure. Dogs and cats likely can't get it, but there is one illness that they can, though it's not common and then really not as bad to them as it is to birds. WIth dogs, cats, other fowl - it's more about them not spreading the droplets that are on the ground to the places where other chickens can be effected by them - they'll be a 'vector' for spread of the illness. That's why you keep animals (and people) from being around her much - just to be safe.
As for eating, keep the eyes cleaned and treated so hopefully they'll clear up soon. IN the mean time, make wet mashes daily with a probiotic (yogurt if you use Tylan, acidophilis capsules if you don't), some honey for taste, a little water if necessary, and her pellets made into crumbles - or crumbles if she's on that. try adding a little mashed up egg (refrigerate what you don't use for the next few days' use). Put some in her beak and keep it in front of her during the 20 or so minutes you're feeding it. Hopefully it'll give her a daily boost. If my birds have a good appetite for it, i'll put the polyvisol vitamins in there. If not, I do the vitamins separate.
Having parrot formula (the powdered formula for baby parrots) is handy, too, in case her appetite drops as it's very nutrient rich and has its own probiotics in it. (If you buy it and use it, don't make it hot - make it lukewarm - hot is for baby parrots and might burn your bird's crop).
In the mean time, trying to keep her nasal sinuses and the mucus clear is very helpful - that's likely to be as much a hindrance; that's why I recommend the VetRx.