It is not used much in the AB/DL community but seen more in BDSM - DD/LG - MD/LB - Ect.I feel like most have one around baby/toddler age.
Myself? I would say I’m 4 or 5.
Does anyone else have an “older” little age?
The term is a "middle" which usually falls between a "little" and a tween/teen or a "big".
A "big" does not always mean an adulting adult.
The ages of each group are not fixed and can also overlap.
So baby, little, middle, and big which usually goes up to "adulthood" or 18.