I think most worlds are good for raising a family. I particularly like Mt Komorebi because it has school uniforms and the festival of youth. But my sims families also like living in windenburg, Henford on Bagley, brindleton bay and sulani.
A playground area with monkey bars or a pirate ship/space ship in the neighbourhood is always nice. Unfortunately we still haven't gotten any toddler playground equipment in any world.
The only worlds which seem less child friendly are forgotten hollow and moonwood Mill but even in those you could add child friendly items to every lot if you want to.
