Well 3 months isn't that much time not to shoot you down, but it isn't. There's still a lot you don't know about her, and one of them includes her feelings of about her EX. She obviously has some feelings either coming back to her about him or ones she never got over. It was very good for her to tell you this, but I also think that's why she hasn't called you because she wasn't sure how to tell you and she was avoiding the situation. Does her Ex live closer to her right now? The only time one doubts anything about theri current relationship is when it is lacking for something they want or need. If she feels this strongly but still wants that closeness as opposed to an LDR then she may be thinking of going back to her ex. I don't want to say this is going happen to make you feel worse I just want to give you how she may be thinking and feeling. I don't know her so I can't say this is for sure.
All in all, you need to give her the space, make sure you tell her at least once that you care about her (don't overdue or you may push her right to him). You could send her flowers with a little card that says how much you care. but other than that I think you just ahve to giver her the space she needs to think. Unfortunately!
If you can't handle the thorns, don't crave the rose!!