My Cousin Is Secretly My Mother's Daughter

Synopsis

The Queen Dowager suddenly fell gravely ill while praying. The king issued an order to choose a noblewoman to attend her illness at Fivefold Peak. My cousin, Nancy Barrow was chosen. My mother cried endlessly and begged me to go in Nancy's place. She said, "Your cousin lost her parents young and is frail. If she went, she might never come back. "You trained in fighting skills with your father since childhood. You are healthy and strong. Why not go in her place?" I couldn't bear my mother's endless tears and agreed. I went to Fivefold Peak for three years. When the Queen Dowager finally recovered and returned to the capital, I rushed home, only to find my mother holding an engagement ceremony for her daughter. But I was still at Fivefold Peak. Who exactly was my mother marrying off?