Mickey Powell, a Pastor I knew had Bells Palsy. Got it in his sixties for the first time. There may be a simple medical reason for it to happen, I don't know whether that is the case. But the pastor was struggling with a problem church, and was very definite about that fact that in his opinion, it was a spiritual attack. This may not apply to your Wife but if it does, my prayer is that you both are led straight to the source of the problem and gifted the ability to deal with it in short order.