Surely you have a cut off on the lower bound below which you don't offer this advice. 21? 18? 16? 13?

Yes, it's possible to put it off long enough thinking you'll find that perfect time, and either it getting to be too late, or perhaps running into the reality that with age comes higher likelihood of birth defects, in many cases. But the flat advice to just do it seems like it's missing a bit of at least a basic foundation advised.

I worked with folks who had kids in high school. They made it work, and had a different cultural background, but nothing about it seemed like the best idea -- at LEAST they had multigenerational households to cover some of the otherwise likely insurmountable difficulties particularly on the budgets they had working service industry jobs.