Can’t be. Since it never happened even though they admit it happened but only in certain...
Oh hell I can’t keep up with the fantasy.
My dads sisters married at 15 men who were 9 years older according to my genealogy records. The marriages were right after WW2. My wife tells me about several of her aunts who married young as well. It wasn't that uncommon and the marriages did well.
There's several things to factor in about earlier mariages in this nation. Education wasn't 12 years but an 8th grader had easilly a high school education offered today likely better as far as practical knowledge. Many persons both men and women married two or more times in their life due to death of spouse from war, disease, death at child birth, etc. Many times it was still during family building years. Location or region also played heavy into it is my guess and the prevailing economics.
In the case of Phil Robertson I think Kay's grandparents raised her. I also think the parents knew him and his family. He was a very capable provider and that was often what parents looked at.