How does the author use foreshadowing in A Great Deliverance?

Stepha Odell is an exceptionally beautiful woman, a fact that cannot help but foreshadow her brief encounter with Lynley later in the text. Stepha is also indirectly connected to William Teys, and she knows Teys' whereabouts, which make her suspicious. In addition, the presence of two of Ezra Farmington's paintings in Keldale Lodge foreshadows the discovery of his one-time relationship with Stepha.