If my memory serves me correctly, the term, Little Girl has been around a long time in terms of "Lolita"s. One only has to know the story to understand the concept, basically adult male pedophiles who are attracted to underage females, hence: Lolita. Adult babies have always been under the radar of society, so our term of "little", be it little girl or little boy is almost unknown or unheard, because most of society has no knowledge of us and what we do. This is why we have begun to refer to those who haven't a clue as Muggles.