It sounds to me like she's been honest with you about things, I don't think she's done anything wrong to be honest, other than perhaps that she should have initiated that conversation herself and not waited for you to do so. I get that it hurts you, that you want her to be totally into you and for the ex to be consigned to the past, but it sounds like she won't even know how she feels herself until she sees him, and I don't think it's unreasonable that she should go and meet him and figure that out - it's not like she's demanding you wait in the wings, that's a choice you're making for yourself. There's every chance that when she sees him she will remember why it was they broke up in the first place, or that she just won't feel the same way and seeing him will be 'closure' and make her feel more ready to move forward with you. Equally it's possible that she'll reconnect with him and that sucks for you but if that's what happens then better that you know that now at this early-ish stage than months down the road when you're even more emotionally invested.