In what ways can Ivy be described as the antagonist in the novel, A Lost Lady?

Over the course of the novel, it becomes apparent that Ivy is determined to destroy the Forresters. In a move that some people believe is helpful to the Forresters, Ivy has rented the meadowland from the Forresters and is farming it. Niel believes it is out of spite to the couple that he drained the land that Mr. Forrester once thought was so pretty. Even while Mr. Forrester is still alive, Ivy makes a habit of making himself at home on the Forresters' property. He dictates how the Forresters can help him, for instance, he demands Mrs. Forrester provide him lunch one day. Ivy also treats Mr. Forrester in a way that is both hateful and disrespectful. At the conclusion of the novel, Ivy has convinced Mrs. Forrester to turn her back on all of the friends that she and her husband once had. He has also encouraged her to invest money in his illegal ventures.