How does the author use foreshadowing in While I Was Gone?

In the late 1960s, Jo was in a marriage that she found unexciting, and she worked as a teacher and found that work unfulfilling. One day she quit her teaching job and soon thereafter took a job as a waitress at a bar. The bar exposed her to a life she had not previously experienced, and it created a desire for more adventure. Soon she moved to the Boston area without telling anyone of her true intended destination. Under an alias she moved into a group house inhabited by other young, free, and adventurous people. A violent tragedy involving a friend ended Jo's time of a carefree life. I think that her move for adventure foreshadows her experiences where she feels "over her head" and "drowning."