Along with Reverend Hale, Elizabeth Proctor undergoes the most significant changes in The Crucible. In keeping with the theme of personal responsibility, Elizabeth comes to accept and admit her role in the affair between John Proctor and Abigail, recognizing the fact that she has flaws like her husband.
At the beginning of the play, Elizabeth pushes John Proctor to do his duty and to act in ways that make him uncomfortable. This is, at least in part, a way of punishing Proctor for his affair with Abigail. She is cold and distant and righteous.
As the play moves on, Elizabeth puts aside her victimhood at the very moment she becomes a victim of the witch trials. When she is accused of witchcraft and arrested, Elizabeth is not indignant. She refuses to enter into suffering. This is the first change in her character.
The final change in Elizabeth comes when she confesses to John Proctor that she feels she played a part in driving him to have an affair. She tells Proctor that he is good and that she is sorry to have put all the blame on him for so long. This is a final step away from the role of the innocent victim.
At this point she is no longer innocent, by her own account, and she refuses to play the part of the suffering victim. She preaches strength to her husband and displays that strength herself.