I think it would be extremely unfair for a rat that has been growing up in the wild to suddenly be imprisoned. I imagine she is very scared and it is possible you could get bitten. Wild rats can carry diseases which humans can catch such as Leptospirosis, and you would have to have many tests done by a vet to see if she is carrying anything.
Rats wash each other, play games together and use each other as fluffy pillows.
My advice is set her free. This includes refuse too. They will be forced to go elsewhere to find food. If you want to go back to 'the best pets ever' I would like to suggest you go to your local animal shelters to see if they have any. In my area there are always many sweet rats waiting for a loving home.