Susan was very happy in her life in the London of 1963 and the Doctor forced her to leave with him when she tried to she threatened to depart from the TARDIS with Ian and Barbara in the Junk Yard!
JB
Well there was rarely any family relationships seen in the early series. The rough and low down council estate stuff only began in the new 2005 series although Ace's friends were from council housing in survival in 1989!
JB
Susan was his Granddaughter and not his niece. He did force her to leave 1963 while kidnapping her two schoolteachers for a trip around the universe!
JB
Oh, Buddha...just let her crap fade away, why bother to give this codswallop a ending when it has no respect for the show's history!!! Erase it from canon and the gender-bending rubbish that never existed before chinballs and Moffhack had to ruin it!!!! If they do bring it back ignore everything...