We visited this site several times when faced with Lily’s cancerous leg and I would like to pass along our experience.

The vet told us she would be jumping half as high as she used to and two months after the amputation she would be running around happy as can be. Bullshit.
That may be true for a young cat but Lily was a healthy outdoor alpha female of 13 years. That translates to 60 something in human years and it took her much longer to recover.

It has snow been six months and she can jump up on a chair but that is about as high as she can go, no more going over a six foot fence. She was depressed for at least two months but catnip helped, she has always loved the stuff. Her stump muscle was invoked whenever she had her left neck scratched and when she got up to move she was very crooked/twisted in the direction of the amputation. She still is for the first couple of steps even today but once she gets going she can be surprisingly fast.

There were a lot of feelings of guilt and concern along the way but now we are happy to have her with us and she is happy too. She is still outside much of the time and still thinks she is a toughie occasionally chasing off a neighbor cat or swatting at her sister.
A few drops of Rescue Remedy in her water bowl may have helped, my wife thinks so. The catnip definitely did help and so did frequent brushing and a lot of neck scratching where she no longer had a leg to help herself with those pesky itches.
It took six months to fully recover but now she seems like the cat we have known for all these years, healthy & happy.