I have no problems with SD. No problems at all. I like it this way. I achieve this by having absolutely nothing to do with her! I have her number blocked and her FB blocked. I don't go anywhere she might be. I don't invite her to anything. This is the only way that I've found that keeps all the stress, drama, and gut wrenching mental pain away. If I have any interaction with her whatsoever there is a good chance it might get twisted around in some manipulative creative way that ends with me hurt and somehow looking like the bad guy.
SD18 calls DH yesterday and it suddenly turned into a heated argument. She got livid with DH because he would not drive over to her house (next town over) and mow her lawn for her even though it was almost dark outside. She was going to prom and having a party at her place afterwards. She wanted her house to look nice for it. DH refused and eventually hung up on her after he told her to stop talking to him like that.