There is something about this in the book "The complete ball python" by kevin mccurley. I have been doing some research on this, Since I am in the same situation with one of my Mojave males (I have a thread on here about it). It is a defence thing since these snakes do not have "mean" as a mood. She is really stressed or really scared for whatever reason, Or it could just be in her personality.

Its like people, You get some mean people, then some that wont harm a fly.