Speaking as a fully paid up Bar room Agony Aunt, and with a course in psychology under my belt, several degrees from the university of life I would say she is taking great satisfaction from F***ing up your life, probably doesn't realise how it affect you but gets a buzz from knowing that you still care. She probably gets in touch when her present relationship is not providing her with the expected levels of comfort and wants someone to adore her. For your own peace of mind and in order to progress to new relationships uncluttered with painful history give her the BIG E next time she phones, hard I know but you need to do it for yourself and this is one occasion when you can be orgiven for being entirely selfish