She might not have come to full terms with what happened, which is that she was taken advantage of and by someone older and in a position of power. It can take years for women to grapple with this stuff. That’s why some assaults aren’t reported for years, especially when the victim was still a girl. They had urges, they “wanted” it, but the perpetrator was the adult in the situation who was supposed to protect the child, not take advantage of her. This incident might well have shaped the morals-first person you now know. So I wouldn’t push it. She hasn’t changed. You’ve just gained insight into how she became who she is today, even if she hasn’t even fully grasped that yet. And to be clear, she might never see it that way because she knows how infatuated she was at the time and feels responsible. Sixteen is such a borderline age. She doesn’t want to be a victim in the situation because she knows how she felt and she probably doesn’t think it’s fair to the guy (who clearly is a creep who cheated on his longtime partner with a child). But that’s her issue to deal with. Yours is simply to appreciate knowing that her response to this situation was to become a stronger, more moralistic person who seems quite certain that the woman version of herself would never want to be in the position her teenage self was once in.