How does the author use foreshadowing in Looking for Mr. Goodbar?

In pages 182-217, Theresa's time alone is a turning point in her attitudes. The writer foreshadows here some changes that Theresa might have been capable of if she had not been murdered. The idea of seeing a psychiatrist, the fact that she did not turn James down immediately, and the fact that she sent Tony away all prove that she might have changed if not for one man who took away her right to change.