Hello huon, it takes courage to share that, thank you. I too was abused by an older sister, she is four years older than I and she was abused when she was four or five. Please know you are not alone, that others share that burden but that there is hope for comfort and peace in the near future. You are on the right path, keep doing what you are doing. When you are ready, share your story as you can, getting those memories into a healthy support group like ours helps to untie those feelings of shame and regret, helping us to realize we were not protected by those who's responsibility it was to do just that.
You are not alone,