Lots of kids is the way I've been playing Sims 3 since it came out... is pretty much how I played Sims 2 as well come to that. it's not much more difficult to raise a half dozen than it is to raise two really, as unless they're born very close together the eldest will be old enough to lend a hand with raising the youngest, although as with any large household the pause button is your friend. Unlike a lot of people, it seems, I enjoy playing babies and toddlers and I set myself challenges with them, for example to see how many lifetime reward points I can get with them before they age up... my current best is around 1800 before aging to toddler and over 5000 before aging to child. By the way toddlers can read books to themselves if you leave them on the floor for them... and I discovered today that the speed at which they read if they're in the library is phenomenal.
To be slightly more relevant, so far my single mother founder has two pretty little girls and I really should get round to updating my blog with pictures of them.