We have just been through this(see post about lone hen from about dec. 1 or so from me). Our SLW was alone after something got our Sussex. She was miserable and confused. We consulted on the forum and got wonderful advice, including how long (if) to quarantine for one hen...someone not far from us, introduced through BYc, kindly gave us 3 chickens about the same age-our loner is 8 mos. And 2 pf the newcomers are about 5 mos., one about 9 mos.
We put a chicken wire fence between them in the pen and henhouse. the SLW (Lorna)was curious and seemed very happy to see potential mates-she kept close to the fence and ate in their feeder a ticking her head through to their side. We gingerly let them into the same space after 2 days, while we stood there to monitor and it went well....minimal chasing by Lorna. Each day we let them be together more and a week later they were roosting together. All barriers are down and Lorna serial chases and pecks a bit at the other 3 but it's pretty halfhearted, just to show them she's been here the longest. maybe we got lucky by getting 3 docile ones even though one is a JG and will be bigger than Lorna eventually.
we are new to this and I know we took a chance with cocci and other diseases that might be in the ground but we had no choice I think given the situation and it is getting (has gotten) COLD here in upstate NY.
good luck with whatever you decide. if she was used to having just one friend, one might do it. then, as they get to know each other you can breathe while you decide what to do next, if anything. it's hard to make changes in winter, depending on how cold and dark it gets.
It is so hard to see them lonely-anthropomorphizing or not, there was no doubt Lorna was bewildered and sad.