i had my meniscus surgery in september... there will be minimal movements for a few weeks... just do the stretches and excercises they tell you too every day and she will be back to normal in no time...
my tear was a "bucket handle tear" which apart from completely tearing the muscle is one of the worse ones...the only problem i have right now is i cant fully bend my knee 100%... so no crouching... its about 85% right now... and getting better everyday..
good luck!