It might be surprising when you are not at the receiving end of it, that it is hard to trust or forgive our loved ones when they have betrayed our trust. That is not to say that as humans we will never ever break the trust of our loved ones. Both are natural and normal things to happen. You both need to have an empathetic perspective on it. As I see it, open communication about hurt and human frailties is in order. You could probably, with her point of view in mind, still talk about how you understand that she is hurt and you want to help her process it as much as you can. She would need to understand that you are truly sorry and bringing it up, again and again, may not help heal the rift and establish more trust for the future. Also remember, ‘getting in touch with your past’ to prove a point, to punish, or simply because of your discomfort at being taunted is not going to help the situation at all. You don’t deal with trust issues by chipping away at them more. Your getting frustrated about it may not help her get to a point of reconciliation that is beneficial for both of you. Assertive, patient and kind communication is your best bet.