Alright, I have a very complex method, but it's well worth it and quite foolproof. Please follow my instructions to the letter!
Stop doing whatever it is you're doing to necessitate being guarded with your BB info.
If that doesn't work, I have a workaround.....
Ask her jokingly if she's been nosing around in your BB. Her response should speak volumes.....not as much as the original post, but volumes nonetheless.