I think that Creepy Little Girls ultimately are derived from Creepy Older Girls. These have an interesting history.
The Elvira and Vasmpirella types derive, arguably, from Vampira and Morticia Addams. All are dressed-in-black vampiresque ladies with long (or big) dark hair. These, in turn, probably owe a lot to Mora, the companion of vam,pire Belas Lugosi in Mark of the Vampire. this, in turn, was a remake of 1927’s [B[London After Midnight**, in which vampire Lon Chaney Sr. had a female companion Luna, played by Edna Tichenor. She, I maintain, is the original Creepy Girl. She had forbears in literature, but hers was the first realization on screen. Dark hair, dark-rimmed eyes, very still and unmoving, staring, terse or unspeaking (even in a silent flick, she didn’t get many lines).
She was pretty young, too. It isn’t hard to imagine a younger version of her. If Morticia was Luna by way of Mora, then Wednesday, in the 1930s and 1940s cartoons of Charles Addams, was the little-girl version.