The leading cause of death for girls 15 to 19 worldwide is not accident or violence or disease; it is complications from pregnancy. Girls under 15 are up to five times as likely to die while having children than are women in their 20s, and their babies are more likely to die as well.
History tends to take the simplest possible view. As soon as you start to scratch the surface of any historical event, it starts to become more and more complicated, which is not the stuff of Hollywood films. Complications tend to break down the budget.