Thank you, KMCINVA. There is/was a feeling that changed the family dynamic after I disclosed this. My sister was just as much a victim as I was.
I guess what I learned through all this is that even though there were adults involved, people did the best they could despite the challenges. I know my sister loves me (and I of her). But she did the best she could at the time. While I may not have agreed with some of her choices, she did what she had to do at that specific time. And I can move on from there regarding my feelings toward her.
FYI: She tried to save her marriage and get professional help for him. But he was too far gone, so she divorced him. Before she walked away, she had to exhaust all her options to help him before the divorce. At the time and even now, I don't agree with some of her decisions, but I can at least understand her point of view. She has remarried and has a beautiful daughter. So I am happy for her in that regard.