Firstly, many thanks for your comments and good wishes regarding the little cat Sammy.
I checked in with Sammy first thing today. I didn't know how she was going yesterday: phone calls receive a recorded message. Today she looked, mostly, like a proper cat. Fur dry and fluffy, eyes alert, not glazed over. Face not so good. I rang later today after x-rays were taken and, amazingly, it's "just" a broken jaw, a lot of soft tissue injury plus infection. Jaw broken too far back to do much about other than let it heal. Her eating shouldn't be compromised when it heals. She's walking properly so the spinal injury was bruising and swelling (yay). She is very anaemic, so must have had a big bleed after the accident. Being fed via nasogastric tube at the moment, but Sammy can lap water. She will come home when she can eat.
I asked the vet nurse if Big Bills can be paid in installments: yes, they can. Thank goodness, as this will be a Big Bill!
I think Sammy may have used most of her nine lives now. This is what the vet said when we brought this very borderline-for-survival cat in, "Cats are the most robust of animals, they survive trauma that would kill other animals, including humans".
Well, yay for cats.