"Dirty Children" or "Dirty Child" refers to an individual(s) who lead a rather undesirable lifestyle such as a Prostitute, Stripper, Drug Dealer, Gang Member or other social deviant(s).
An individual with squalid living arrangements is a "Dirty Child"
An individual sloppily dressed, who is foul smelling, and is cloudded with uncleanliness is a "Dirty Child"
Women and or Men that partake in exceedingly lascivious and smutful acts with multiple partners are "Dirty Children"
Any person onto which you feel to be of lower class or status, financially and or socially can and should be refered to as a "Dirty Child".
You are walking down the street with your friend and spot an exceptionally beautiful woman, who upon further examination you know to be a swash-buckling, scally-wag of a pirate hooker and you tell your friend the following:
"Dude, seriously? That bitch is a "DIRTY CHILD", who ain't been with that ho?! That shit is "DIRTY CHILDREN" fo sho!