The grown-up goes first and does more.
All this talk of growing up is fine, but how do you get your wife to do it?
Yeah, it’s a trick question – sort of.
The grown up thing to do is to do all you can, even when your spouse is doing far less than they should. Being grown up means taking responsibility, and that can mean doing something your spouse could or should have done. Just as a parent does what needs to be done when children do not, the more mature spouse ends up doing more than their less mature spouse does. Similarly, just as our examples teach our children far more than our words, being adult and responsible with regards to our spouse is likely to do more than nagging.
If it’s her who needs to grow up, and it’s really bad, some level of confrontation will become necessary if your example does not bring change. This is usually better done with third party help.
If it’s you who needs to grow up, PLEASE choose to “Just Do It!” It’s no fun, and it takes time and hard work, but anyone who puts their mind to it can grow up.