What do I do about a stepdaughter that ruined my marriage 5 years ago? She is still ruining my life.?

She was 20 when her dad and I married. She always had control over him even when he was married to her mom. He moved away for a year when she was 12 for work and she moved and lived with him,his wife did not go. Four counselors said she became the surrogate wife to him, and she has never been put back in the "daughter" role since. She thinks she is the wife. They went on weekend trips together, hiking, dinners, movies, etc, etc, etc. and the wife was content to stay home. The daughter wouldn't let her interfere with her relationship with her dad anyway. To this day she still finds ways to make my life miserable. Help! She got what she wanted, her dad divorced so she could run the show.