Ask her this question. Just be calm, adult and direct: say, "I really care about you and because of that I want to be sure that you are totally comfortable being back together. Do you want a break?" If you keep the tones constructive and relaxed, you will be amazed how much real communication you will get, not just old tapes and arguing. If you start to hear undercurrents of old grievances in your own tone of voice, give the conversation a rest until you are more genuinely ready to hear whatever comes up. Good luck!