Dr. Who question: Who was Susan Foreman's mother?

I just saw an episode on Netflix of the revised series in which the Doctor has a genetically replicated daughter. (Why she was the only female on the planet is beyond me, but that's a whole other question.) Her name was Jenny, and she regenerates at the end, after the Doctor has already left.

Anyway, he mentioned having lost another daughter, whom I assume was Susan's mother. Who was she? Was she also genetically replicated, or did the Doctor get some action? Did she ever appear on the show?

BQ: Do you think that Susan was the mysterious female Time Lady in The End of Time?