THE SMART TRICK OF SEX HIEP DAM THAT NO ONE IS DISCUSSING

And someone may possibly use it to emphasise that their little ones have still left residence or are not dependent on them. But you wouldn't introduce anyone as "my adult baby/ren".The term stays "children" despite their age. It is possible to elaborate on that with "grown-up youngsters" or, much more awkwardly, "adult small children" but for anyon