There does need to be some age adjustments in this game. There could be the following ages:
Newborn (birth-3 months)
Infants (4 months to 1 year)
Toddler (1-3)
Chilld (4-10)
Young Teen (10-12)
Teens (13-19)
Young Adult (20-40)
Adult (40-65)
Elder (65-death)
This is the closest I could come to making a change to the ages in the game because kids in this game seem to go from looking like toddlers to looking like they are 11-12 in the game with nothing in between. And then make adjustments to the Teens, Young Adults and Adults to make them more distinct.