She may change for a short period, but in the end her old ways will win out. Change has to be done because the person needing it WANTS it, not because others want it. You can't just break up with someone and expect that to fix problem central to them. The world doesn't work that way. Look, most relationships DO NOT work out. It is what it is, so if you aren't happy, break up with her to be happy, not to change someone.