You have made a good decision and I hope your parents' friends can come through. Ally has reached a point in a her life where she can only feel aggression towards other living beings so this may be the beginning of a better life for her - we will all hope so. I know you will feel guilty because we all do, no matter what extreme measures we have taken to care for our pets/fosters, but no-one here will believe you should feel any guilt at all. You have always gone way beyond what anyone else would do to care for Ally.

My rescue group who places in barn homes that are unheated use lots of straw bales and blankets to create snuggle places within the barn. Of course, if there are other animals in the barn (large ones that she won't want to bite) their body heat will help.