I’m 40, and few of my peers are unmarried with children in my area. They are either married with children, or have no intention of getting married or having children. I know that this pattern is very different even with people only 10 years younger than me; I can’t believe the number of 30 year-olds I meet who have children with somebody they never married and are no longer involved with. I remember girls being single mothers, but that seems to have occurred when they were between 16 and 20 years old (back when I was that age).
I don’t see the Church having any practical advice for people who have been raised outside the faith, and on top of that the Church’s efforts seem focused on helping other groups first.
I mentioned the Church’s role because the article is about marriages in the Catholic Church. If those numbers are dropping for any reason other than simple population change, then it’s an issue people should be addressing in that context.
That said, although numbers of Catholics seem to be increasing, it’s possible that we’re at a low point in the number currently at the usual age for marriage. That would be the children of people now 50-ish, kind of tail-end baby boomers. Maybe they had fewer children than average.
The people I know have more than average, both the ones my age and 5 to 20 years younger. Even on the swim team, a group with no obvious selection other than being at the pool, I’d say the median is 3 per family.