only tell her what she needs to know; don't talk about your own personal life or about any other co-workers' habits or problems. just busy yourself with your own work, and don't feel compelled to satisfy all her questions. some people are just very nosy and intrusive where they shouldn't be.
"You just concentrate on your job, and let me worry about mine! I've got work to do now. Please bring me the Peterson file."
Sounds like you better step up your game. She sounds like me when I show up on a new job. I learn everything, not just the crummy job I was hired to do. Nobody ever likes the new guy that learns fast and has the ability to do it all.
I throw a hex on her and get her *** gone, if your feeling says she's bad news. Just take out the trash is all it is, nothing wrong with that
This seems really fishy, i say keep a distance and tell her that her asking about how to do your job makes you uncomfortable or naturally change the subject when she does. Good luck.