How do characters change throughout the story?

In The Edible Woman, the main character changes throughout the story. The main character Marian changes drastically throughout this novel because she starts off being a gentle sensible woman, slowly changes into a woman full of regret, sadness and disappointment, and then evolves into a stronger smarter woman at the end of the novel. She starts off thinking she loves Peter, and then changes into thinking she only needs him, and finally she figures out that she is better off without him. Marian changes her personality throughout the novel, along with her relationships. The relationship she has with Peter changes because she loves him and wants to marry him, but then she changes her mind and she does not love him anymore. The relationship she has with Duncan, a man she met while working changes as well. When they first meet, she thinks he is quite strange, "I was convinced that he was a compulsive neurotic of some sort and that I'd better remain calm and not display any fear"(pg.55). He looked younger than he was, however later on they meet at a laundromat a couple of times and they become friends, secretly. Duncan and her at the end of the novel reveal their secret friendship to Marian's friends, which is a relief.