Although I was afraid to look the next morning, to my delight the chicken was still alive, just sitting--but at least she was sitting up. After taking a head-count of the other Ameraucanas, I determined that it was Pepi-Two whom Hero had attacked.
I continued to keep heat under her, offer her sugar-water and crumble, and keep her covered up in our closet all of Thursday. There was no sign of her eating or drinking, but her bodily functions seemed to be performed, so she must have been eating something!
Finally, on Friday morning, I suggested to Herb that we couldn't keep her in our dark closet forever, so what about seeing if the other chickens would take her back? We know that sometimes chickens will actually peck an injured chicken to death, so my plan was to observe them very closely and remove Pepi-Two at the first sign of violence. We set her in the chicken tractor, and she made a bee-line for the food. She ate ravenously, then drank, then ate some more, then drank some more! And the other chickens acted as if she wasn't even there. So our "reunion" ended up being a non-event, which was really nice since we'd had all the adventures we wanted since our return.
Writing this on Oct. 18, Pepi-Two continues to do fine, running around with the other chickens and not apparently fearful at all, compared to Chickadee who still panics into a flapping flutter every time she sees Hero. Considering that all she had was a sore foot while Pepi-Two lost half her feathers and got bloodied, I think Pepi-Two has earned her title, "the Brave."
Hero, on the other hand, continues on house arrest. He gets to run out in the morning until the chickens are let out, then he's only allowed out on the leash until after dark when the chickens get shut up. He is not a happy camper! However, he is also still living in his good home, so he really can't complain!