I'm so sorry for your loss!
Could you maybe do a started pullet? Something almost mature? Maybe that would be hard with winter coming up and introductions, just thought I'd throw that out there as an idea. I think everyone else's ideas are really great though. When two of our three died we ordered a couple of started pullets for her and it worked out well. We got ours from Murray McMurray.
I hate to rain on the parade, but I would expect you to loose the last one too. In my experience this has happened. Chickens are often not real long lived animals. If I got another chicken, I think I would try and get two or three. Or you may end up in the same place.
As for the house chicken idea, I don't think a bird that has lived outside all her life will be comfortable in a house situation. Chickens hate change.