Gayle is the sister of the novel's main character Faith Harrington. Gayle died of an non-disclosed form of cancer. She was a music teacher and singer, and often gave advice to her sister. Gayle was the reason for Faith's choice of job and lifestyle, and the inspiration for much of Faith's life choices.
Even after her death, Gayle continued to influence Faith's life. In fact, Faith often recalled things that Gayle used to say to use as advice. In September 2004, Gayle appeared in a dream Faith had, in the form of a bird. The Gayle-Bird was killed by Faith's boyfriend, Oscar Wolfe.