My friend's little girls have a bunch of silkies that are around 7 months old. This morning when S went to go let them out and feed and water them they all came running to her but one. Upon inspection she had one eye that was completely crusted shut and the other was open but had puss in it. I told her to immediately quarantine the chicken and give it separate food and water and put a little ACV in her water bowl. She was going to clean her eyes with a warm washcloth and as soon as I could find out anything I was going to call her back. What else should she do and is it contagious to the rest of the flock?