Life is long and the millenials have much to go through. Compare how baby boomers were in the 60's and 70's with how they are now. That generation once thought they knew it all. There is no knowing what joys and sorrows will come into the lives of your son and future daughter-in-law. But they will encounter both. And they will end up being glad of supportive parents. She may gravitate toward her family. If you blame her every time you have an issue with your son, she will dread being around you. Let every adult be fully resposible for his own behavior.

From what I've seen, grandmothers become very popular when new parents find how hard child rearing is. Young couples envision life going along smoothly. Then reality hits.

I know a happily married young couple who told me how their families operate. When they have a fight, his mother encourages him to apologize to his wife. Her mother encourages her to apologize to her husband. Those are two very smart and wise mothers. They are also very loved.

You saw your son learn to walk, then learn to read and write, etc. Now his task is to learn to make a successful marriage. Maybe he will succeed. Maybe he won't. Half of marriages fail. Be rooting for the success of this upcoming marriage. Don't worry about whether his s.o. acts the way you think she should. They have to please each other. They'll figure that out between themselves, or they won't. That's their problem, not yours. Don't burden your mind too much with what is between them. Not your problem. Be a gracious host, when they visit. Find things to complement. Be courteous. Don't take up mind reading. What people think in the privacy of their own heads is their own business.

If they are sometimes immature, realize they haven't lived as long as you have.