No, this is not normal, but I also have relatives and friends who are ultra-involved with their daughters. It dismays me, as I also have a daughter in her early 30's, and she doesn't do this at all. Dismays, because these friends/relatives seem to thrive on this kind of behavior. My humble opinion is that we are supposed to let our adult children go live their own lives.
As for your situation, Startingover12...I don't know what you can or should do, but the wife needs to start separating herself from the daughter a bit...a lot! If she is not inclined to do this, then you will have to decide if this is okay...or not. What to do beyond that, I don't have any constructive advice, since such behavior is usually deeply ingrained.