The History of Humāyūn (Gulbadan Begam) 161: CLXXXI. Shahr-banu Begam Miran-shahi (No. 7).

161

Third daughter of ‘Umar Shaikh Mirza Miran-shahi and Umid Andijani; half-sister of Babar and eight years his junior; born cir. 1491; full-sister of Nasir and Mihr-banu; wife of Junaid (brother of Nizamu-d-din ‘Ali Khalifa); mother by him of Sanjar Mirza; widowed cir. 944 H. (1537-38).
She seems to have gone to Sind with her nephew, marriage to Afzal Haidar Mirza throws some light, and it is that when Shaibani had murdered her brother, Mahmud Khan, Afzal left him and joined the Uzbegs [Kazaks] of his own people, and Sultan-nigar followed him into Moghulistan.
She had two daughters by Afzal, one of whom married Abdullah Sultan and died a young wife, and the other married Rashid Sultan (Chathan).
On Afzal's death, Sultan-nigar married his brother Qasim (presumably in conformance with the Turk custom of yangi-lik).
With Qasim's death, the headship of the horde devolved on Sultan-nigar's son (or a step-son by a co-wife) named Tahir. Tahir was, says Haidar, "very much attached to her, and even preferred her to the mother who had given him birth."
When, following the fall of Tahir and his half-brother, Sultan showed her appreciation of Tahir's affection, but petitioned him, saying: "Although you are my child, and I neither think of nor desire any one but you, yet I wish you to take me to my nephew Sultan Said Khan. For I am grown old, and I have no longer the strength to bear this wandering life in the deserts of Moghulistan; take me where I can enjoy some quiet and repose." She then offered to mediate for him and to obtain the support for him of the Moghul Khaqan against his foes. Tahir accordingly escorted her to the Moghulistan borders, and with her waited upon Said. The latter, from love of his aunt, rose, saying that although his rising to receive Tahir was contrary to the rules of Chingiz (their common ancestor), yet that he did it out of gratitude because Tahir had brought his aunt.
Sultan-nigar died of a haemorrhage in the summer of 934 H. (1528).