A few weeks ago I purchased three chicks from a local farmer. Two are barred Rock and one is a mixed breed ( barred rock and Unidentified father). The mixed breed chick, we will call her jo, has always been tinier than the other two but I have noticed they are growing and she isn’t. Last night she seemed weak and not as active as the others. I took her out of the brooder and she slept on my chest thinking she’s not getting enough heat. I tried to feed her as well and she didn’t eat. How can I get her to perk up and healthy? What’s going on with her? What can I do?