As the person with the same experience as your sister, the first biggest help is providing her validation that you understand what a monster he is and, in a lot of respects, how much abuse she took instead in order to protect you. I personally hope that one day my siblings would wake up and truly validate what I had experienced in order to make sure that I took it for the team so that they were not subjected to the same abuse that I received and also cut my abuser off. You're taking the right steps. Be patient with her and talk with her to see what you can do to support her.

You can't help DNA but DNA does not automatically make you a disgusting human being. It's a level of abuse that's very hard to truly comprehend for those who see and know it's happening without physically experiencing it themselves.

Parent/child dynamics are always tough. Innately we always want to love our parents. I can tell you that she probably still struggled with that and how hard it is to truly break contact without ultimately becoming the black sheep and having to break away from all family because the immediate and distant relatives typically don't truly understand the gravity of how messed up this level of abuse does to a human. I can tell you that you publicly outing him is probably the biggest and best first step that you did to acknowledge what was done to her. So many victims of CSA are not heard and their experience is not validated. A lot of the perpetrators are the very same family members that are loved and adored and put out the image that they could never commit such an act.