Oh, OK....you didn't really explain what you meant, that normally she waits for it.
Certainly no joke, & personally, I'd modify the way I feed so that never happens again...since you cannot depend on the accuracy of snakes in feed-mode.
So were you alone when you fed her? If so, you should really re-think your safety protocols, IMO...she's a growing girl, yeah? Can't depend on luck & reflexes.