I'm in Arkansas, about 15-20 miles south of Fort Smith. I do have MFLs, but mine aren't laying yet.
dlarimer was who I was going to recommend. He is intensively working with them, but he isn't actively selling any. He would probably send you something to work with though.
Sorry for your loss. Around here it would probably be a skunk or racoon. Set a trap, catch it, determine how to keep this from happening again, go get some more chickens and get back in the game.
I really just looked here to see what Ridgerunner's answer was. He does so well explaining things. My advice would have been through her in there and watch what happens. If it gets to rough for her take her out and try something else. If it does get to rough try housing her separate but...
I think it is widely accepted, 4 square feet per bird for coop and 10 square feet per bird for run. But, more is better especially when it comes to chickens. Letting them free range during the day certainly will help, but keep in mind there may be days that you won't be able to let them out...