It will be a few months before your baby will be close to 100%. Did your surgeon talk to you about any type of physical therapy? or did he talk about supplements?
Hot Rod had his surgery a year ago the end of March and from time to time, he still picks his leg up. At each of his vet vists I have them look at his knee and it is a tight as it can be.
One of the my regular vets told me that it can take up to a year for recovery.
I would think for sure that after 6 weeks your surgeon/vet would have you doing some type of physical therapy. We were able to do water therapy for Hot Rod at 5 weeks. Best of luck to the both of you. Hugs.