aging up a newborn in sims 4

Newborns age into infants.  The sims 4 did not have toddlers or babies unattached to the bassinet when if first came out.  Toddlers came out many  years ago, and infants came out before the Growing together expansion.  If you are new to the game, I will let you know that infants behave differently ( have a lot more things they can learn ) if you have the Growing Together expansion.