Sharon (The Big Bang)

Sharon was Amelia Pond's aunt. She was also the great-aunt of River Song.

Biography
In an alternate timeline, Sharon was Amy's childhood guardian. Amelia had lost her mother and father to the crack in her room, which had erased them from existence. Sharon had moved with Amelia to Leadworth some time prior to Easter 1996. (DW: The Eleventh Hour).

It is apparant that Sharon and Amy did not share a close relationship; Sharon often left Amy alone in the house as a small child and, when told of Amelia's meeting with the Doctor, she refused to believe her niece and instead arranged several psychiatric appointments for her.

In yet another alternate timeline in which all the stars were destroyed in 102 AD, Sharon took Amelia to the National History Museum in 1996. Amelia dragged her around and then ran away to find the Pandorica. After Amelia went into hiding, Aunt Sharon looked for her, but failed to find her. (DW: The Pandorica Opens (TV story))

After the cracks in time were finally closed by the Doctor, the rightful timeline was restored. Amy had now been raised entirely by her parents, and Sharon had not become Amy's guardian. Sharon attended Amy's wedding and witnessed the return of the Doctor on June 26th 2010. (DW: The Big Bang).

At some point, Amy dreamt that she was a child in the 1960s and that her aunt was with her. However, Amy quickly deduced that she wasn't real and eventually disappeared. (DWM: Forever Dreaming)

Trivia

 * So far, it has not been stated which of Amy's parents Sharon is the sister of, Augustus Pond or Tabetha Pond.