Who is the protagonist in this quote and about how old is she? What has the mother just revealed to her and why does her mother make this “strange” request? How does Rosie respond and why?

Suddenly, her mother knelt on the floor and took her by the wrists ‘Rosie,’ she said urgently. ‘Promise me you will never marry!’ Shocked . . . by the request . . . Rosie stared at her mother’s face. Jesus, Jesus, she called silently, not certain whether she was invoking the help of the son of the Carrascos or of God, until there returned sweetly the memory of Jesus’s hand, how it had touched her and where. Still her mother waited for an answer, holding her wrists so tightly that her hands were going numb. She tried to pull free. Promise, her mother whispered fiercely, promise.