A friend has a cat enclosure that attaches directly onto the house so her puddy can come and go as she pleases through a cat door, but is always contained and safe. The enclosure has logs, grass and plants in there and its big enough to stretch her legs a bit so its not just a little cage ITMS. It also gives the cat an opportunity to lie out in the sunshine on grass if she wants too, which is kind of nice.

I think though that some cats are happier outside than others (mine would never leave the house, specifically the bed) given a choice!), but they can adapt and its a whole lot better than the alternatives. I hope she settles into her new home soon.