i have a rule, no one younger than 5 yrs older than my kids, for two reasons.
firstly as quite rightly was said, what on earth would you have in common.
my late husband was 11 yrs older than me, and we had a chasm of differences about how the world is perceived.
secondly, it would feel just yukky to imagine getting all gooey eyed over someone that could be my own child.
yes age is just a number, but some things are just best ……left alone