I agree with Hankster that the best approach to use is to gird up your loins and tell her the relationship just isn't working for you. To be honest, I see the ignoring behavior as less mature (eek--don't flood me with reactions to that!) Of course, sometimes ignoring does have to be done. I do think people are often owed a reason, so at least they can get some feedback and have the chance to do better. Again, as Hankster said, maybe she has never been told how she alienates people before!

That said, there are people IRL that I don't make it my business to be around--but they were never close friends to me anyway.