Cat watery eye?? Advice!!

I have a six month old kitten. When I came home today, she had her eye held closed. Upon closer inspection, her eye is very very watery. It's clear discharge, I don't see any puss or anything. I haven't heard her sneeze or cough, but it's running profusely and dripping off her nose. Seems to be bugging her, she keeps rubbing it. Wondering if maybe she injured it? I feel bad, it's Friday and unless this is an emergency she won't be seen by a vet until Monday. I do have some eye drops (tobrex) that the vet prescribed for our other cat that was never used (his eyes at at that point got better on their own.) but I'm afraid to use it in case there is an injury? Advice? Does this warrant calling the vet in and pay the emergency fee? If this is an infection, is it contagious to my other cat?

I would not suggest using eye drops ment for another cat, im sorry to hear ur baby isnt feeling well, it could be acouple things, if youre cats play together the other might have knicked her in the eye, or she might be showing symptons of conjunctivitis , thats what happened to my baby Dante is he had clear watery eyes, and it progressed into a much larger situation that im dealing with, but if you can afford to see a vet now I would go rather then wait, if it was you with something bugging your eye you would figure out what it is and fix it rather then wait, that can be uncomfy for the kitty especially if it is a scratch it could get infected, sorry for misspelling of words, im typing on a smart phone

You can take her to the vet. They will numb and stain the eye.  If you can obtain it without going to the vet I would try PolyBac for starters.