How does Ruth assist Selina in her deceptions in the novel, Affinity?

When Selina Dawes comes to live with Mrs. Brink to help her contact her dead mother, Ruth becomes Selina's maid. Ruth caters to Selina's every need and eventually they begin a romantic relationship. Ruth then takes on the persona of Peter Quick, Selina's spirit guide, and helps Selina get lots of money from those who believe Peter is really a spirit.