“But in the five years when the first-born is between the ages of 13 and 18, that increase goes up to 5%. And it peaks, at 9%, when the child is 15.”
"between the ages 13 and 18, parents of first-born girls divorce more than parents of first-born boys. The odds of divorce within this period are 10.7% for parents of boys, and 11.3% for parents of girls." https://theconversation.com/parents-of-teenage-daughters-mor...
There are 2 ways of spinning this. 10.7% to 11.3% is only a 0.6% increase in "absolute" terms. In "relative" terms it's a 5.6% increase, but that sounds worse than it really is. If you start with a very small number, then almost any increase no matter how small represents a significant increase in relative percentage.
There are lies, damn lies, and statistics.
The alternative way to look at it is that 89.3% vs. 88.7% don't divorce, which makes it a relative difference of 0.7%.
The do-divorce is a 5.6% increase, and the don't-divorce is a 0.7%; both are derived from the very same numbers.
There's also the dubious assumption that increasing the divorce rate is a bad thing. Kids can sometimes suffer more from an unhappy marriage than from divorce. Especially older kids who are more aware of the situation.