When Anakin was a toddler, Shmi and her son became the property of Gardulla the Hutt, and were brought to Mos Espa. Gardulla subsequently lost the pair to the Toydarian named Watto. Though none would ever confuse Watto with a humanitarian, he was nonetheless a fair owner who afforded Shmi and Anakin their privacy. Still, Shmi wanted more for her son than the life of a slave.
The opportunity came during Anakin's ninth year. A Naboo delegation led by a Jedi Master was stranded on Tatooine, and the ever-generous Anakin offered them shelter in the small hovel the Skywalkers called home.
The Jedi, Qui-Gon Jinn, sensed great Force potential in Anakin, and arranged for his freedom. Unfortunately, he could not free Shmi from slavery. Shmi said a tearful farewell to Anakin, knowing that his future lay in the stars beyond Tatooine. Anakin promised to return and free his mother, but he did not know at the time that the life of a Jedi precluded such personal missions. Adherence to the Order meant abandonment of his previous life, and it would be years before Anakin returned to Tatooine.
Watto, rendered nearly destitute by his chronic gambling, was forced to sell Shmi. A moisture farmer named Cliegg Lars had fallen in love with Shmi, and purchased her freedom. The two wed, and Shmi became a loving stepmother to Cliegg's son, Owen. They lived a quiet existence on the Lars homestead as moisture farmers, forming a strong bond of a loving family. Still, Shmi looked to the stars with an empty ache in her heart for her son who had left long ago.
A month prior to Anakin's return to Tatooine, Shmi left the safety of the house in the early hours of the Tatooine morning to gather mushrooms that collected on the moisture vaporators. A raiding party of Sand People suddenly attacked, and Shmi was kidnapped by the bandaged brutes. Outraged and grief-stricken, Cliegg rounded up a posse of moisture farmers to rescue her, but the Tuskens lay in wait. After a bloody ambush, only four of the 30 farmers returned, including a maimed Cliegg.
A month passed, during which Cliegg reluctantly accepted Shmi's death. Anakin, who had been plagued with nightmares about his mother's safety, suddenly arrived at the Lars homestead. Cliegg told him the terrible news, but Anakin refused to accept that his mother was dead. Borrowing Owen Lars' swoop bike, Anakin sped into the twilight desert in search of Shmi.
Shmi was barely alive, relying solely on hope to sustain her beaten form. She was held captive at a Tusken camp, beaten and starved. She knew, somehow, that Anakin would come. She weakly opened her blood-caked eyes to see her handsome, grown son enter the Tusken tent and free her from her bindings. She whispered her love for her son before finally succumbing to her wounds.
Anakin, enraged at his mother's death, lashed out at the Tuskens. He slaughtered the entire village, killing the male warriors as well as the females and children. Shaken and terrified by the power he awakened, Anakin quietly returned to the Lars homestead with his mother's body.
Shmi was buried at the Lars homestead at a quiet funeral. Cliegg spoke of his love for his wife. Anakin felt shame for his failure to protect her, and promised to never fail again. Sadly, this was but one of many promises that Anakin would break.