The future queen became a
kollotaw of Prince Mindon at the age of 14 together with her sister. Upon King Mindon Min's ascension to the throne (r. 1853–1878), Khin Thet was granted the royal title "Thiri Thu Sanda Mahe" (သီရိသုစန္ဒာမဟေ, ) and became one of the queens of the Royal Treasury (ရွှေတိုက်စာရင်းဝင် မိဖုရား). Later in his reign, she received a higher title, "Thu Thiri Ratana Devi" (သုသီရိရတနာဒေဝီ, ), formally recognizing her as a Devi-ranked queen—one of the highest distinctions bestowed upon a queen consort in the Konbaung dynasty. She received the appanage of and was therefore known as Thetpan Mibaya (the Queen of Thetpan). She was part of the queen faction led by
Kunitywa Mibaya, which opposed
Hsinbyumashin, the Queen of the Central Palace. Other members included Limban and Nanda Dewi, the Second Queen of the Northern Apartment. In 1877, the group petitioned King Mindon to prevent Hsinphyumashin from being appointed the new chief queen following the death of Chief Queen
Setkya Dewi. During the final days of King Mindon, Queen Hsinbyumashin wielded considerable influence over court affairs. She ordered the arrest of several princes and installed her protégé,
Prince Thibaw, as the heir to the throne. In response, a faction of queens appealed to the ailing king, reporting her irregular actions. However, King Mindon died shortly thereafter, and their appeal was never addressed. This massacre nearly led to the extinction of Thetpan's royal lineage. A later source suggests that she was fortunate to have a grandson through her younger son, Prince Taungnyo, and his concubine Me Ya, a Thai noblewoman. Me Ya is said to have escaped execution and fled to the Kyaukgaung near the Thai–Burmese border, where the child was born and raised in exile. However, Thetpan and her grandson were never reunited. ==Issue==