I tend to agree with those who say avoid a workplace relationship. If it goes bad, it makes for workplace weirdness and you don't need that.
Likewise, I can tell you as a manager of 25 people, she doesn't even have to say "stop" to you in order to report you for harassment. All she has to do is tell the HR department that you've made her uncomfortable in some way, and then you're marked, and again, workplace weirdness is the result, with the added benefit of it spreading to the HR people.
So, if you are unintentionally sending her vibes, find out how and quit it. Clarify the situation with her as a misunderstanding and tell her (nicely) that her attempts at reading your mind are making *you* uncomfortable and agree with her not to bring up the subject again. Record the date and time you had the conversation with her because you might need it if the aforementioned conversation with HR occurs.
My personal opinion is that she may well be interested in you (as discussed previously). Find out if she is and decide if you want to deal with the risks and/or rewards as they may be. If she isn't interested in you, then you've clarified the situation and you can get back to work.
