Shmi and her son Anakin lived as slaves on the desert world Tatooine until 32 BBY, when they sheltered a Jedi Knight Qui-Gon Jinn from a sandstorm. The Jedi and his companions took a great interest in the talents of young Anakin, and when the time came for the boy to enter the Boonta Eve Podrace, Qui-Gon made an arrangement with Shmi and Anakin's owner Watto: Watto would give Qui-Gon the parts he needed to repair his ship and free Anakin if the boy won the race. Qui-Gon tried to free Shmi as well, but Watto refused to give up both slaves. However, Anakin won the race and his freedom and Shmi encouraged him to find his own path without her holding him back. As mother and son said their goodbyes, Anakin promised to return one day and free Shmi.
Sometime after Anakin departed from Tatooine, Shmi was sold to a moisture farmer called Cliegg Lars, who freed her and married her. In 22 BBY, Shmi was abducted by Tusken Raiders, who imprisoned and tortured her. A month after her capture, Shmi's son Anakin - now a Jedi Padawan - returned to Tatooine in order to find her. After learning of her capture, Anakin tracked down the Tusken clan that had taken her and found her within their camp, tied up and badly beaten. Anakin released Shmi from her bonds and she told him how proud of him she was. As Shmi struggled to utter her final words of "I love you" to Anakin, she died in his arms.
Shmi's death would have an extremely dire affect on Anakin, who took his first great step towards the dark side of the Force by slaughtering his mother's captors in a vengeful fury.