My Mom/Dad had 2 Boys at ages 24/26 and 30/33.
My Uncle had 2 Girls (twins) at age 42; and then 1 Boy at age 44
My Paternal Grandparents had 3 Boys at ages 25/29, 26/30, and 27/31
My Maternal Grandparents had 1 Boy at ages 21/26; and then 1 Girl at ages 26/31.

I have all the Geneological records my Grandfather had collected over the years, before he passed away. So, I've got records showing the approximate ages my ancestors back to the 17th Century [when they were still having 12 or more kids per mother] were when they had their kids and what Gender they were. I don't have time right now to analyze them, though.