We live in a culture in which young girls grow up and are told they can be astronauts or anything else. Their futures as wives and mothers are hardly thought about.
Both young men and women come out of college at age 21 or 22 and are focused on careers or just having fun. The last thing on their minds is marriage and family.
For those who do think about marriage and family, many want to put off thinking about it, thinking they have plenty of time in the future for that.