Woman with a Box

Here's a question for you.

I'm reading Agatha Christie's The Pale Horse and in passing she mentions "the Woman with a Box" as if it were a common folklore concept. (Pandora?) I'm curious because the new novel also features such a character, a crone with a box containing death as a dark aspect of the Earth Wife. It always freaks me out when I re-invent something. I swear to you, I came up with the Three Faced God long before I encountered him/her/it in Indian mythology.