I've had both knees replaced. Be sure that she does her therapy and with a little time everything will be even better. Tell your bride that we're all rooting for her rapid recovery.
Your wife will be amazed at the improvements. If the therapist tells her to do 10, do 11. The first month is a little uncomfortable, but after that, she'll be thankful she did it.
Prayers sent!
As mentioned above, the physical therapy after surgery is no picnic, but must be done to have 100% movement/flex. Had my left knee replaced in 2012 and it's as good as my right one.