A major knee dislocation doesn't sound good! You don't say how old your Mom is or how fit she is or whether she's anyway educated in (self-)rehabilitation. Trying to keep costs down by not having physio may well have serious consequences for daily living and normal activities if she doesn't manage to regain good movement and strength. She'll probably need good fairly detailed instructions on what to do when to regain function and someone to check how she is managing. The surgeons who operated should give her guidlines. Not everyone can get back to normal by themselves. A physio sounds a very good idea. False economy is not always a good idea unfortunately. I'm not sure of the situation in Canada but do your best to get advice!