She reminds me of my vindictive ex-wife. We both knew six months before that we were going to get divorced some time in the future. So, she started laying the groundwork beforehand.
She started trashing me to anyone, and I mean anyone, who would listen. The mailman, our doctor, all her friends, all my friends, my family, her family, people at my workplace, ANYONE. Her motive was clear. She wanted to make sure that when the divorce happens everyone knew that it was justified and NOT HER FAULT! While I understand her motivation, her tactics were childish and self-defeating.
I kept telling her that she was making a mistake. I kept telling her to keep it in the family. But she could not help herself. She craved the sympathy. While she was doing that, I had only praise for her.
She did 'blacken my name' throughout our greater community, but she was trashing herself at the same time. All these people were thinking was, "My God! He sounds like a horrible monster! But...but...you married him. What does that say about you!?"
And it came to fruition. After the divorce she was no longer invited to barbecues, community events, parties, weddings, etc. Her people began to think of her as someone without adequate judgement or discretion. In trashing her husband, especially in such a vile and exaggerated way, as my wife, she was essentially trashing herself and her whole household. This left a bad taste in people's mouth. I do not know if she ever recovered.
I see echos of that situation in what the sister is trying to do to Trump.