Age through the ages

Jane Austen's Bennet girls go husband-hunting to avoid becoming old maids

On the eve of my 25th birthday, I was thinking about what a woman my age would have been doing in the past--because she certainly wouldn't have been single and working on her PhD even 50 years ago. So, to put it in perspective:

Ancient Greece: Girls were married between 12 and 14. Under that plan, I'd probably have an 11-year-old child by now and I wouldn't be able to leave the house much--women were confined to the house.
Medieval Europe: By age 25, a girl could have been married for anywhere from 7 to 15 years already. If she could even read, it was unusual, and she probably signed her name with an X.
Jane Austen's England: By now, at least being educated is seen as a good thing for a woman, although your education was long over by 25. Given that Jane Bennett in Pride and Prejudice was 22 and considered at the edge of being an old maid, it didn't look good for a single 25-year-old--she'd be a financial burden on her parents and seen as a spinster.
My grandmother's time: By 25, my grandmother was married and had given birth to my aunt and my dad. She didn't get to go to college, and she kept busy taking care of the kids while my grandfather went to work and college on the GI bill.

So, where does that leave me? Clearly, with a very different life at 25 than women who came before me, but what I really can't fathom is having children already. Most 25-year-olds I know--male or female--are more interested in making a life for themselves and finding their passions than in starting a family. Does having time to find our passions make us happier? Or would we be happier married and settled, expectations laid out for us? Let's just say I think I make a better student than a housewife or mother at this stage.