She was fine today but I just went to see them. She is all fluffed.
Temp is 75F and others are fine.
I saw she eat and drink but not acting as she used to.
That's not really enough info for us to be much help. If you look at the sticky at the begining of the emergencies section you will find a list of questions. Copy and paste those into a post (ask the mods to move this to emergencies) and answer as many of the questions as you can.
At 5-weeks old my first thought is cocci, but can't say for sure without a better idea of their diet, living conditions, etc.