How would you address this?

Sometimes...

ultra Charismatics actually do believe they are doing the Lord's will by allowing the "Holy Spirit" to do what He wants. Of course, this is anything but holy and if it's not a tic, should be confronted with gentleness. I would ask to speak to the lady and tell her exactly what you shared with the forum here - that her movements are distracting you and probably others from the actual service. If she says she won't quench the Holy Spirit, be armed with a scriptural defense: "This is not God moving your arms to distract from worship...the Holy Spirit does not act unbecomingly...etc.

As a pastor's wife, I say it like it is as gently as possible, but don't avoid truth. Yes, she may be offended and even leave, but you have come to her in love and concern - for her and those seated around her.