How does the author use foreshadowing in The Liars' Club?

Creating a sense of mystery by the technique of foreshadowing is a part of Karr's array of novelistic techniques. The mystery is created when Grandma Moore shows Mary a photograph of two children, whom she calls Tex and Belinda. She tells Mary that they are Mary's brother and sister. Mary does not understand what she means, since she has never seen these children. Grandma says the children were sent away, and if Mary is bad, she will be sent away too. The full story does not emerge until the last few pages, when the adult Mary learns from her mother the circumstances under which Tex and Belinda, her mother's two children from her first marriage, were taken from her mother. The fact of that terrible loss explains Mother's history of mental problems. As in a good mystery novel, the author produces the solution only at the end, which also enables the memoir to end on a note of reconciliation and optimism.