Townies life progression.

So I've scanned through the forums and couldn't find what i was looking for... I'm playing my first gen going onto my second gen, and I haven't really noticed any sims being introduced into family's (new babies), my sim is in the doctor career and delivers babies often, is this a rabbit hole type situation or will these townies then have these children? I have been playing the sims 4 since release and still haven't figured out if townies life progress without my help (marriage/have children etc.)