I know this is not the same situation, but years ago, when I was a child, a chicken wandered into our garden. She had her neck feathers all plucked and we guessed that she had escaped from being sent on her way to slaughter. We kept her as a pet and she adapted wonderfully and became a much loved pet. She laid a few eggs in the next couple of years although we did not want her for that purpose, she was a family pet. She even got on with our dog, a golden retriever! Her favourite food was melon and peas, she used to live out in the garden shed and spent her days pecking around in the garden. She lived approximately 5 or 6 years and we very much missed her after she had gone. By the way we called her Henrietta!
Cheers Sue