Have you already had the sit down talk with her? I would allow my hope to live until that happened. If she still wants to break up or if she cancels the sit down (which it sounds like she might have done?), I would let the hope go at that point because it is really out of your hands. It has been a while since I dated, but I remember being in similar situations and sometimes it took me longer than others to get over the idea that we really weren't getting back together. I also remember three months being a milestone when a lot of my relationships ended.