When Xuande became emperor in 1425, Sun was promoted to the title of Noble Consort. In 1427, she gave birth to a son. As the empress had not given birth to a son, the son of Sun was made crown prince. In 1428, Sun herself, the mother of the crown prince, was promoted to the position of empress.
Upon the death of Xuande in 1435, her son succeeded to the throne being still a minor. She was however not named regent; her power position as the mother of an under age monarch was undermined by the influence of her mother-in-law, Empress Zhang (Hongxi), who became regent in her stead. In 1442, her son was declared of legal majority.