If she invited you it might benefit you to go. Don't dwell on what you think the reasons are....regardless of what they may be. We all have those things in our past that make for "oh my God" moments but it does not serve us to dwell on them. You have to forgive yourself first and then have the others forgive you later. Forgiving yourself first allows YOU to heal and then deal with those others (whether they forgive you or not). At least you will have already healed yourself. Hope that makes some sense?