Shmi Skywalker is a fictional female Human in the Star Wars film series who was portrayed on screen by Pernilla August. Shmi Skywalker is a slave owned by Watto on the planet of Tatooine. When Anakin Skywalker is given the chance to become a Jedi Warrior, she lets him leave with Obi-Wan Kenobi and Qui-Gon Jinn.
Shmi states that Anakin was the result of a virgin birth in that she wasn't conceived in the same way as any other person would. It was speculated the birth was the result of midi-chlorians, tiny organisms that help control the Force within a person. We know that Darth Plagueis was able to control life, not only take it away but also bring it back as he told Anakin during a chat. It quite possible that Palpatine, Plagueis's apprentice could have been experimenting and made Shmi Skywalker pregnant.
After Anakin leaves to begin his training, Watto sells Shmi on to become a farmers wife. Just before Anakin visits, Shmi is kidnapped by Tuskan Raiders where she is tortured and dies when Anakin comes to rescue her.