... may have been best when there was value to child labor and extended families were a norm. Where few educational opportunities for younger people existed and old people had to rely on large families for care.
I also know a family with young mothers and grandmothers. Almost all ended in divorce. Or do not have to register the marriage. In such families often "tradition" in the repetition of the situation. I do not know what it is justified. Earlier there was a different situation. My great-grandmother was married at age 14. She did not want this marriage, but nobody listened. Her parents gave her to the man, which today might be called "a successful farmer." She did not like him, but he loved her very much.
My mother in law - on the contrary. She married at age 30. Well, she was 17 years old when started the war. She was a participant. When the war ended, she was 21 years old. And it was a girl with military awards and character as a rock. She chose a husband for a long time. My husband, her son, was married too in 30 years. He was seriously prepared for this. I suspect that our oldest son to do the same. So I'm not a grandmother soon.