Of the other 5, which one is "alone"? I'm mean which one is off by herself, on the outside looking in, or otherwise not buddied up. That's the one to bring in with Hawk.
If there's a flockmate she's particularly close with, you may want to bring that one in with her. Chickens aren't usually happy alone. They like companions.
My independent Twirp lost her tail feathers to a dog, hid, was out all night, was found and fished out from DEEP inside a juniper bush...