"rogue's girlfriend, beggar's mistress," 1520s, slang, of unknown origin (see dell (n.2)). Liberman says it is probably from Low German dokke "doll," "with the deterioration of meaning from 'sweetheart' and 'wench' to 'whore.'"
late 14c., "red with heat, heated till it glows red" (of metal, etc.); in reference to persons, "lively, passionate," it is recorded from c. 1600. Red-hot mama is 1926, jazz slang, "earthy female singer," also "girlfriend, lover."
female proper name, shortened form of Mollie, Molly, itself a familiar of Mary. Used from c. 1600 for "prostitute," but in low slang by early 19c. it also meant "female companion not bound by ties of marriage, but often a life-mate" [Century Dictionary]. It became a general word for "woman" in old underworld slang, for instance Moll-buzzer "pickpocket who specializes in women;" Moll-tooler "female pick-pocket." U.S. sense of "a gangster's girlfriend" is by 1923.