I think for a lot of human history, getting married and starting a family before 20 (for women) was borderline scandalous. Cultures that solved the housing problem by normalizing several generations living in the same house started a couple years earlier. I think most women, who want to join the workforce, would be best served by getting their education and a couple of years of on the job experience first, so 24-25. Getting married a couple of years prior wouldn't be bad. From my anecdotal experience, having and raising children changes the focus an functionality of the brain in ways that aren't great for higher ed. From a societal point of view, we should normalize women taking a dozen years off for the family, allow some education catch-up, and welcome them back to the workforce without adding any crushing debt or negative consequences. A lot of women don't really enjoy motherhood and would rather be at work, so having systems where part-time work is normal would be good too.