How old are sims?

Babies are weird in sims games, I feel like they are solidly about 5 months old, I can't even justify saying that they "age" at all during the time they are babies since babies rapidly change so much in real life - a newborn and a one year old are such radically different human beings lol, but could both be considered a baby.

Toddlers solidly feel like two years olds.

And then for the rest, I agree with the OPs age ranges