In Star Wars: Episode 2 Attack of the Clones Anakin learns that his mother, Shmi, was sold to Cliegg Lars, and was consequently freed by and married to him. Clearly this happened sometime between episodes 1 and 2 but how long, exactly, after Anakin left Tatooine did this transaction take place?
A few comments on the question Why Didn't Qui-Gon Free Shmi Skywalker? have been suggesting that Amidala should have been able to go back and buy/free Shmi after the events in Episode 1. Would that have been an option at that time (did Watto still own her?), or had she already been sold to Cliegg?