The length of her nails seems to indicate that she has been somewhat lame for quite some time, long before you found her incapacitated. What I mean is, she has been unable to scratch normally to keep them trimmed because she cannot support herself on one foot and scratch with the other. Feel her thigh and leg muscle on the side with the curled toe and compare it to the other leg to see if the muscles on the curled side seem atrophied. I think you're going to need to do some gentle therapy to keep the afflicted leg in good condition by gently flexing and straightening it from hip through toes. Take it slow and easy and don't attempt to straighten everything out right away so you don't tear delicate tissues, it will take time and patience. Good luck with her.