Sheldon told Amy that they’d have to agree on whether they’d raise their kids to prefer the Enlightenment or Renaissance period of history.
Interestingly, The Big Bang Theory actually dropped some hints that some kids could be in the works for the happy couple.
At least two children are on the way for Sheldon and presumably Amy, given their wedding just before the Season 1 finale of Young Sheldon went off with only minimal hitches (and one Mark Hamill).