Word of advice. Don't try to play armchair psychologist when someone who actually studies psychology is in the room. Especially not when you're just trying to get out of a rhetorical corner you painted yourself into.
But a child is not looked at the outside but the inside. For an example there can be a 7 year old girl that is very mature. She is physically 7, but on the inside she is mature and acts like an adult, so I will refer to a child as who they are inside of themselves.