Sometimes I notice a bunch of one gender. I've had households with all boys or all girls. I find it kind of interesting. I don't think I've had 9 or 10 in a row. I had a household of 4 boys though one was a born-in-game adoption. (I had him move in with his aunt as a toddler and he's grown up with his cousins as brothers).
I figured that the game was trying to balance itself out. I like gender to be a bit unpredictable. I also have households of varying sizes. For the most part, I avoid influencing the outcome. I sometimes take the radios out to keep sims from autonomously playing one of those radio stations.
Just to be clear, I know the difference between gender and the other scientific word that probably can't be used on here.
Anyway, sometimes I delete townies, so I didn't realize the impact that can have on the balance. I also rotate around though so if there are a bunch of boys or girls, they usually get spread among different households.