Ditto to what everyone's saying! I too was wondering why your "friend" was telling you this? Especially at a time like this? you're trying to work on you right now, you're doing you MF and kicking butt at it, you've got a great promotion and should be able to enjoy that, and one thing you do NOT need is stress and a things that bring you down right now! Maybe she is indeed the jealous one, or the one who likes to stir things up? (Maybe she's the one who's talking??) Only you know your friend, so this is just an initial reaction to it on my part....
Also, even if they ARE talking, so what! I know it's easier said than done, but you EARNED it. THey are just jealous if they are talking, and that's normal to some extent, not fair, but normal. It'll pass tough. Just go back there and be your normal professional self at work, friendly but professional. If they were truly your friends or even friendly before, they will be again!
By the way- CONGRATULATIONS!!!!