SHE WAS JUST HUNGRY.
Bite + constriction = feeding response strike
Quick nip and release = defensive strike
You didn't feed her for 20 days, she was certainly just feeling that she needed to be more opportunistic when it came to food, and thought your wrist looked like a nice warm mammal. You just ended up being more than she bargained on
If you want "SCARY", try handling a 12 foot southern scrub python that is intent on tearing your face off.. lol.
If you're really scared of her, wear gloves and long sleeves. I do this with young carpet pythons who are pretty darn nippy in general. The primary reason isn't protection (though gloves can provide some), but to limit the heat radiating out of my hands and arms. Pythons have heat pits and use them to hunt, you just showed up on her infrared and looked tasty