I'm seriously confused by our feelings for each other?

It sounds like you have a very strong bond :) If she's been with somebody for 6 years, she obviously feels dedicated and loves them very much. It sounds like you were happy flirting with each other, and then things started to move up to the next stage. It becomes very awkward when this happens, because you will both feel things you don't want to feel, and then things you want to. Often you'll want more, and possibly more than that, you'll want less. You'll miss the friendly, chirpy, light relationship you had before. Try going out for a movie, or just a coffee or something. Not as a date, because you both sound happy were you were before, unless you want to try and win her over. But a movie might make you become more of a friend based relationship if thats what you want. Or throw a party or some social event where its not just the two of you. :)