Tuam, Ireland CNN  —  When Annette McKay’s first grandson was born, she thought her mother, Maggie O’Connor, would be over the moon. She had become a great-grandmother. Instead, McKay found her sobbing unconsolably outside her home, crying: “It’s the baby, the baby.” McKay reassured her 70-year-old mother that her great-grandson was healthy. But O’Connor wasn’t talking about him. “Not your baby, my baby,” O’Connor said, revealing a secret she had buried for decades. Her first child, Mary