All broody hens will go crazy when a chick is removed, especially an only chick. But for both chicks to bond with one another, and be a pair for the years to come, I would put the other chick with in the brooder with it. The easiet thing to do is to grab the boody hen and place her in a pen or...
Welcome to BYC. If you can get to a feed or farm store, or even a Walmart, get a brooder lamp, preferably with a red bulb (most are 250 watts.) Put a thermometer under the warmest part of the brooder with the light at least 18 inches from the chick's head, with a cooler area to get to. I would...