This has always confused me. While I'm pretty aware of who's infant, baby, toddler, the word young always bowls me out!
How the age is classified based on the range of the years? For instance,
How many years a very young child will be? Any range? It's even confusing when you remove child from there - That's her! In her very young age. - What's the age now? In her adolescence? Childhood? Early childhood?
An answer with a good reference will be helpful. I hope it's not something an opinion based.