Mirror Image — Danielle Steel

To look at one was to see the other. For family, it was a constant guessing game. For strangers, the surprise was overwhelming. For the twins Olivia and Victoria Henderson, their bond was mysterious and marvelous-a secret realm only they inhabited.
They were the beloved daughters of a man who never fully recovered from his wife's death bearing them in 1893. shy, serious Olivia had taken over the role of mother, managing not only their lush estate, but her rebellious twin's flights of fancy. Free-spirited Victoria embraced the women's suffrage movement and wanted to change the world. Then, in their twenty-first year, Victoria's life was about to become a public scandal. Handpicked by the twins' father to save her reputation, Charles Dawson thought he could make an unwanted marriage work. But in an act of deception, the twins took an irrevocable step, sending one of them to the battlefields of France, the other into a marriage she longed for but could not have.