Wow you have had a bad week
I hope your nana is doing okay. If she needs to go back to the hospital again and the snow is still bad you should ring for a PTS ambulance to take her in, they are using 4x4's at the moment so it will be safer to travel in one of them then trying to drive a smaller car. I work for the ambulance service and can PM you the number to book a PTS ambulance if you want it just let me know.
I hope things get better for you soon, it sounds like you have had a nightmare of a week and I hope you have a great Christmas. xx