Deceiving Mirror — Margaret Yorke

A still young and attractive widow, Nesta Falconer has made a pleasant life for herself, living with her fifteen-year-old daughter Philippa in a cottage close to her brother-in-law's farm. She divides her time between voluntary work and managing Charles Falconer's household after the breakdown of his marriage. But this satisfactory arrangement is threatened when her sister Claire returns unexpectedly from America and comes to stay at the cottage. Charles gradually realizes that Nesta menaces Philippa's happiness, and that she has been responsible for much distress in the past. With the advent of realization comes change, and life begins to assume different colors...