Thanks folks... I think I just got a bit too hopeful with the improvements. We buried the little girl today, my daughter cried. Very sad, but she is free from the suffering of her illness. I feel silly being so sad over one Silkie out of a dozen, but you really get attached to the ones that need so much nursing like this.
Today I'll be bleaching out the area that she was in, bleaching the rest of the waterers and feeders, and put the other 3 back out, as they have continued to do just great. I've certainly learned to keep Cocci meds on hand, and next time I will know what is going on a lot faster than this time.
I guess now I can go back to worrying about my eggs in the bator- this is my first hatch and I'm sure I've killed them all by now, LOL.