If the emperor succeeds with an illegitimate child, his biological mother is the empress dowager, and if his first mother exists, she is also the empress dowager. The first mother is usually above her biological mother. But if the biological mother is too humble to be called the queen mother, she can only be honored as the imperial concubine at most, but she can be righted as the queen mother in the future.
If the emperor takes sideline as his heir, his stepmother (the queen of the first emperor) is the empress dowager, and he must admit that her stepmother is the first mother, and her biological mother still maintains her original position, so she will not be named the empress dowager.
Extended data
In China, there are many queens who hold enough power to rival the emperor. The representatives of these queens are:
Emperor Gaozu, Empress Dowager Han Huidi and Empress Dowager Han Shaodi: Lv Zhi.
Han Wendi, Han Jingdi and Han Wudi: Dou
Empress Dowager Cixi, empress dowager of Xianfeng, Tongzhi and Guangxu emperors in Qing Dynasty.
Usually, the positive evaluation of the queen in power is not very high, but there are also some virtuous queens, such as;
Empress: Actually, it is the Empress Dowager, not the Empress Dowager.
Jin: Chu garlic
Empress of Northern Wei Dynasty: Empress Feng.
Empress Liao Taizong and Empress Liao Taizong: Shu