Wow - big job to do all that painting!  I bet it looks great & you're eager to get back home.  I don't know the specific answer to your question. 

As far as I can tell from what I've read, and from experience, better quality latex paints dry pretty quickly & the fumes generally dissipate within a day or two.   We've been doing a bit of painting here too ... and I do notice that I get a bit wheezy - feel like I'm getting a cold - by the evening, but it's gone the next day.  I think it's a bit of reaction to the primer we're using though, not so much to the paint.   So I guess, use your common sense - if you notice symptoms, wait a little longer.

As for brain development concerns - you may be thinking about lead based paints - they have been banned for many years now.  You do need to take great care if removing or sanding old paint though.  Latex paint does not have lead in it. 

Enjoy that fresh new home - and your growing family!