She married Mehmed in 1449, when he was still a prince and the governor of Manisa. Just before Sultan Murad II's death, she gave birth to her only son, Şehzade Mustafa, who was to be his father's favourite. According to Turkish tradition, all princes were expected to work as provincial governors as a part of their training. Mustafa was sent to govern Konya and later Kayseri, and Gülşah accompanied him.

Mustafa died in June 1474 of natural causes. It was said that Mustafa had approached Mahmud Pasha's wife and thus making him behind Mustafa's murder. There are speculations that Gülşah Hatun may have been a party to illicit the relations between the prince and wife of Mahmud Pasha.Giovanni Maria Angiolello, a Venetian traveler, author of an important historical report on the Aq Qoyunlu and early Safavid Persia, was in the service of Mustafa, and who with the rest of Mustafa’s household accompanied the prince’s cortege from his post his Kayseri to Bursa, where he was buried, denied any role for Mahmud Pasha in Mustafa's death;nevertheless Mehmed II had the man executed shortly thereafter.

Gülşah Hatun had not been informed of his death, and with the wagon with her dead son stopped outside the palace, she and the women of her train began to wail. Mustafa's only child, Princess Hani Nergisşah Hatun, shared her grandmother's grief, and the lamentations went on endlessly. Mehmed sent word that she should remain in Bursa with those maidens whom she required. Mehmed also had a good provision made for her, where she might live there honourably. He ordered that Mustafa’s daughter and her mother and rest of the ladies together with all others belonging to the court of his decreased son should come to Istanbul. All the women were lodged in the palace where women of Mehmed's harem stayed, and after several days the maidens were married to courtiers. When Nergisşah came of age she married her cousin Şehzade Ahmet, son of Sultan Bayezid II.

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Wikipedia