When do your sims have babies?

I prefer to turn off aging...it seems sims 4 allows for more creative imagination then past versions of the sims..so if you want your sim to be interesting... you need to combine what the game does give you and then include your own adaptive story line and develop a character who is likable and one you can relate to..that takes time. It is easier to do this with one sim at first and then I like to adapt the town or towns to how that sim chooses to live...usually with something that makes money from home. I might tweak the local library and coffee shop for a writer...or have public garden areas for a future farmer..etc; Then you also need social activities to gather a selective group of friends..maybe that is a night club ..a restaurant...whatever fits the character of the sim. So it is a bit before the main character is ready to meet someone to marry and settle down with. I like the spouse to have a job and excel in that field some prior to having kids...and for both parents to have hardly hungry...seldom sleepy...and steel bladder..then it is time to start a family. I really enjoyed reading what others answered to this question.