Facial physiotherapy after facelift?

Physical therapy after facelift should not impact the results of the facelift in anyway. I would be sure to discuss with your plastic surgeon to make sure that there are no other concerns. 

this far out you should be fine.  most of the healing occurs within the first month.  sometimes when necks are "too tight" I actually recommend stretching exercises.  shouldn't be a problem.

At 3 months, your body has deposited the necessary collagen in order to "hold" your surgical result in place.  facial massage should have very little impact on your result.  Adverse factors such as excessive sun exposure, smoking, and/or large swings in weight are more likely to make your face age faster than what you are describing.