It's only been 3 days. She may just need some more time.

Is she about to shed? One of the snakes I bought was in shed and grumpy as hell when I first got her. After her shed she's been fine.

I'd say:

1. See if she's in shed.
2. Check the temp, hide, and other setup information. Make sure temps are right, she has a place to feel secure, etc.
3. Give her another 5 or 6 days alone.