The villain has been playing badly for ten years

Ning Xiusu, after a decade of playing it safe after time-traveling, discovered the storyline had already concluded long before. Ji Qingyu, the heroine, supported the hero Fang Jinchuan in becoming emperor and changing the country's name to Dayan. Naturally, she became the youngest empress dowager in history, gave birth to a son, and ruled the country from behind the scenes...