As long as you can distinguish what is live and what is memorex, you'll be just fine. Allow her talk all she wants, i.e., whether she's rewriting history or not. She needs to know that you are going to listen, affirm and validate her feelings. Apparently she didn't have much of this as a child. Please do not argue w/her when talking to you about how she feels. Remember...her perceptions is warped right now and what she sees and feels is very real to her.
Continue to focus on you and your children. Give God a chance to work on her a bit.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.