Records of the Three Kingdoms
Liu Bei’s biography says Sun Quan feared him somewhat and married a younger sister to him to fix the alliance. Lady Sun liked military matters. A hundred maids stood in her rooms with knives. Each time Liu Bei entered he was uneasy. That is all the character Chen Shou gives her. He records neither a name nor a courtesy name.
When Liu Bei went west into Yi Province, Sun Quan sent for his sister and she returned to Wu. Pei quotes Zhao Yun’s separate biography: Lady Sun meant to take the heir Liu Shan east with her, and Zhao Yun and Zhang Fei stopped the boats and kept the boy. That is in the notes, not in the main text of Zhao Yun’s life. The histories do not say how she died after she returned. Sun Shangxiang is not a name Chen Shou uses.
Romance of the Three Kingdoms
The novel names her Sun Shangxiang and makes her a princess who can fight. Zhou Yu’s plan is to marry her to Liu Bei so that Wu can kill or hold him. Liu Bei comes to Jiangdong for the wedding, and Lady Sun takes his side instead. Zhao Yun follows Zhuge Liang’s sealed instructions, claims that Cao Cao is attacking Jing, and the couple flee home.
Later she tries to take Adou back to Wu. Zhang Fei and Zhao Yun stop the boats. After Liu Bei’s death, operas and some sequels have her throw herself into the river. That is not in the Records, and it is not a central chapter of the usual Romance. This page uses Sun Shangxiang because storytelling and common memory do.
Reference: Wikipedia · Lady Sun