Meg Hutchinson 
Love Forbidden 

Robbed of marriage to the man she loved, Leah Bryce rears his daugther Miriam as her own. But her bitterness and desire for vengeance lead her to treat the girl with extreme cruelty, and when Miriam falls pregnant, Leah refuses to let her marry the father of her child. Leah’s son Ralph has always loved the girl he believes to be his sister, and fights to subdue feelings that are more than brotherly. When he discovers Miriam’s seducer has no intention of standing by her, he takes a terrible revenge: Saul Marsh will leave no other woman pregnant. But Miriam’s trials are far from over. Her mother’s hatred reaches new and evil heights – even on her deathbed she seeks to ruin the girl’s happiness. Only when Leah’s malign influence is removed for ever can Miriam overcome the horrors of her girlhood to find love and joy at last.