She really needs to go to a rehab location for at least one week, two is better or whatever the surgeon prescribes. Neighbors can take care of her dog and cats and take care of the yard while she's away. You and her should visit several rehab homes before scheduling the TKR to see what one she likes the best, most all of them are fully paid by Medicare. Give them the "smell test" when you visit, does it smell OK and is it cheerful and provide good food too. Get that knee repaired, she can't afford to have a bad knee any longer. I'm glad that I had mine done 3 years ago, have not had any problems since.