According to wwe.com, she dislocated her kneecap. I've done this myself on a might out a few years ago, she'll be out for a few months, possibly longer if she's done ligament damage too.
Since I did mine, I've had to stop playing footy (last time I tried I popped it out again, and it fucking hurts!). If she managed to put it back in place quickly, the recovery will be quicker. Mine was out for about 20 minutes until the ambulance arrived, hopefully it won't be too long.
To give you some idea, Jimmy Bullard dislocated his knee and didn't play foir about 18 months...