How does the author use foreshadowing in The Amen Corner?

Several events in the beginning of Act Three foreshadow the change in Margaret at the end of the play. First, she encounters Mrs. Jackson, a woman in a similar situation to the one she found herself in after losing her baby girl. Though she tries at first to get her to come to God, she reconsiders and tells the young woman to focus on her family. Secondly, in a conversation with Odessa, she tells of her inability to say Amen (which means, "so be it" or "the Lord's will be done") after her prayers. This signals that Margaret doubts the will of God and her own desire to follow it, or at least what she has considered God's will to this point. She also admits to her sister that it was not vision, but fear and grief that drove her to the church. Thirdly, her talk with Brother Boxer, in which she defends herself as a woman and not as a pastor shows us that she is rethinking her position in life. Finally, her brief but heartfelt reunion with Luke portrays her true emotions and desires; she has always loved him.