My wife can go back 7 as well, and her family has also tended towards high parental investment in offspring; next time I'm in the cellar I'll have to check but I'd easily believe they'd also be on the longer side.
(NB. age matching is a post-WWI thing. I believe the pre-WWI ideal was mid-30's men* marrying early-20's women, which seems to have been inherited from Aristotle's recommendation for 30 year olds to marry 15 year olds)
* Stefan Zweig has a chapter on how this gap influenced porn in the Austro-Hungarian Empire — not that anyone in this august assemblage might wonder how the Viennese equivalent of OnlyFans worked.