Description of Covenant Child by Terri Blackstock
Amanda's heart broke as she watched them drive her beloved twins away. She resolved to hope... and to fight for them to her last breath. Kara and Lizzie are heiresses to one of the largest fortunes in the country. But when their father dies suddenly, the toddlers are ripped from the arms of Amanda, their loving stepmother, and given to their maternal grandparents, who only want the children's fortune for themselves. While even the stipend their guardians get for supporting them is squandered, the children are left to raise themselves. Kara and Lizzie grow up believing they are worthless... until the day when they learn the truth.