If they're your friends, won't they eventually realize that you're not hanging out anymore? You have just as much power in inviting them out to do things together as she does. There's nothing wrong with hanging out with your own friends once in a while. It's not like she can do anything about it, and if she tries to do something about it and reacts in any way, that's not bad either. If she gets jealous and starts to try and put you down or insult you around your friends, i'm sure your not the only intuitive one and that your friends will see her for the kind of person that she really is.