Male coders on their 20s are mostly coding and brofounding because they don't have a better thing to do. IMHO It's even not such a good idea to go having babies at this age for a male because you are mostly broke all the time and you are still a teenager.
When people talk about Female founders or coders I think they mean young pretty female founders. There are few, and for good reasons.
I see no shortage of older females in software managament or software arch. positions and many moms are just fine doing startups on their 50s.