I had always thought that it was just a nonsense word she had made up. Before using it here as the title of my post I decided I had better check to see if it might be an actual word so that I didn't use it incorrectly. Turns out it is a real word, and yup, I'm using it correctly.
If you know what's wrong in the picture sing out in the comments.
|*Noun||1.||flibbertigibbet - a female fool|