Well, she didn't make it. The diuretic the vet put her on to reduce the fluid around her heart and lungs was also causing kidney failure, so her condition wasn't treatable. She was euthanised some time today. Our neighbour Carol was able to be there with her.
It really sucks that we weren't able to be there. It's still a real shock how she was a perfectly healthy cat last Friday, and now she's dead.
Sarah's going to really miss her, as she was exceptionally got at being attuned to her (Sarah's) moods. Whenever Sarah was sick or just down, Stumpy would curl up with her.