I see plenty of young soldiers in their mid-twenties who are married to eighteen or nineteen year old girls. It tends to be cultural and they tend to be from the South, and they seem to do just fine. Just my experience.
That’s good news.
I have an ancestor who married at 15 and seemed to have done quite well, too. More than a dozen children in as many years, and the family was quite well loved by others in the area, and she was quite happy.
But I don’t know that I could find any 15 year olds like that today.