As the title states, how do you decide how many kids your Sims have?
Do you have an absolute maximum due to the number of Sims you can manage at one time or that your computer can handle?
Do you calculate a specific ideal family size and then work towards that?
Do you go solely based off the wants of your Sims?
For me, I have ACR 2.0 so I can set an ideal family size and then that is used in the mod's calculations for if they try for a baby or not.
If 2 Sims have a different Ideal Family Size the one that has the higher one has to persuade the one with a lower Ideal Family Size to have another baby once they've hit that Sim's number of kids. So if Dad's Ideal is 4 and Mom's Ideal is 2 and they have 2 kids already, Dad has to persuade Mom to try for another baby. Same if the Mom's Ideal is 4 and the Dad's Ideal is 2. Mom has to convince Dad to have another kid.
I have a formula for that as well that factors in the aspiration, number of kids that already exceed the lower Ideal Family Sim amount, among other things.
I posted in detail here as I put it into place for a BACC I'm doing: https://wildwoodheightsbacc.wordpress.com/how-many-babies/