Born into one of the wealthiest families in the Fire Nation, Ta Min always thought that she would marry someone in the royal family. However, her beliefs changed when she met Avatar Roku and was attracted to his persistence, kindness, and intelligence. Roku had a crush on Ta Min, but every time he saw her, he would become nervous and believed that she did not even know he existed. She was present at Roku and Prince Sozin's birthday when the former learned of his status as the Avatar.
Roku and Ta Min eventually married each other, with Sozin taking the position of Roku's best man. At the wedding, Sozin asked Ta Min for permission to speak privately with Roku. She replied that it was not traditional, but nevertheless allowed the Fire Lord to do so.
She acquired a house with her husband on his home island, and the couple later had a daughter, Rina. Years later, in 12 BG, the couple was awoken from their sleep when they felt the earth tremble. Hurrying outside, they were met by huge clouds of ash from an erupting volcano. Roku remained on the island to battle the volcano in order to give his wife and the other villagers time to escape. Ta Min waited anxiously on a boat, watching her husband's attempts to stop the lava.
Her love for Roku persisted even after his death, as she never remarried. Ta Min quietly lived the rest of her life on Ember Island.