You are going to be working night and day to pull these kittens through their illnesses, and are to be commended for taking on the task. After your first post, I was very afraid we were going to hear that one or more of them had died since kittens fade so very quickly. I remember nursing 3-week-old kittens with URI and how very frightening it was, seeing them mouth breathing and having difficulty eating. The vet had me put nasal drops in one nostril for each cat twice a day, alternating nostrils. I also kept them in a warm, steam-filled bathroom for an hour at a time - I bought a humidifier but I thought the bathroom worked better. They pulled through and I hope your kittens will also.