Babies are fine. TS4 babies are much better than babies in TS2 or the larvae in TS3 where sims would put them down on the floor everywhere and you'd have to go look for them like some bizzare easter baby hunt.
Also, babies in TS4 are pretty realistic. What do REAL babies do more than cry, eat, poop, and sleep? Anything more than that and you are talking about toddlers, which we already have.
If we are talking about more developed life stages, then I'd rather have younger teens, or more details for adults and elders.
