Synopsis: Patricia Polacco shares a never-before-told story about her mother's favorite doll. "My Darlin Trisha, my mother wrote..." So begins the story of Patricia Polacco's mother's favorite doll. Whenever Mary Ellen needed Betty Doll, she was there. She survived blizzards and thunderstorms, attended parties and weddings, and helped mourn the deaths of old friends. From the day Trisha's mother first sewed Betty Doll together stitch by stitch, to the day…