Sadly I think the only way to save her legs is if she's placed back in the hospital with them vacuum sealing them like they were right after her grafts. She was healing so well when she couldn't slip her shit encrusted fingernails into every infected, weeping sore.
Unfortunately that solution would mean she would have to be taking up a hospital bed as well as hospital resources and staff's time, and it would also mean that when she gets bored and starts pulling out her fillings again that they have no choice but to attend to her, rather than someone really in need.
Weighing the options of leaving her to her own stupid devices and having to babysit her and pump her full of extra blood when she remembers that lie I too would just send her home.
I can't remember if she still has roommate or not but they should probably be careful if they leave drinks unattended around the apartment or else the dread pirate Deadlegs might retry the whole "by proxy" thing but on humans this time and give her own body a chance to heal up.
If she doesn't have roomates anymore, and I would not blame them for running because even if she wasn't an insufferable eternal victim I imagine she smells like a greasy bag of rotting hamburger at this point, well then early RIP chomp-cat, if there's any justice in the world the vet will find out what she's using to induce those seizures and she won't be allowed to adopt more animals.
Rates self sadly optimistic