Sharon was Amelia Pond's aunt. When Eleventh Doctor met Amelia Sharon was her guardian, becoming so due to Amelia having lost her mother and father to the crack which erased them from existence, creating an alternate timeline. In this timeline, Sharon had moved with Amelia to Leadworth sometime prior to Easter 1996. (DW: The Eleventh Hour).
In a further alternate timeline in which all the stars were destroyed in 102AD, Sharon took Amelia to the National History Museum in 1996, where Amelia dragged her around until running away and finding the Pandorica. After Amelia went into hiding, Aunt Sharon looked for her, but ultimately failed.
After cracks in time were closed by the Doctor, Amy's parents were restored to the timeline and Sharon had never become Amy's guardian. Sharon attended Amy's wedding and witnessed the return of the Doctor on 26th June 2010. (DW: The Big Bang).