Even though she is 3 weks old I would still put her under a lamp about 85-90 degrees; when they are sick they have a harder time regulating their own body temperature. Try not to force her to drink as birds that are sick and weak are very prone to aspiration and don't have as good of a swallow reflex as healthy birds.
It kinda sounds like a bird I would put down at this point. The kids will have to get used to death one way or another - when you get into poultry of any kind you see it a lot. I think it makes them stronger, more emotionally sound people to have some understanding and experience with death at a younger age anyway.
Be sure to practice really good biosecurity - wash your hands after each handling and preferably handle as little as possible, and try not to wear the same clothes out to your healthy birds. Do the healthy birds first and the sick ones last, just in case.
It kinda sounds like a bird I would put down at this point. The kids will have to get used to death one way or another - when you get into poultry of any kind you see it a lot. I think it makes them stronger, more emotionally sound people to have some understanding and experience with death at a younger age anyway.
Be sure to practice really good biosecurity - wash your hands after each handling and preferably handle as little as possible, and try not to wear the same clothes out to your healthy birds. Do the healthy birds first and the sick ones last, just in case.