User blog comment:IceFireWarden0/Speculations for Season 11/@comment-198.45.201.206-20130729023138/@comment-1886172-20130731014152

Sister wasn't needed in Season 5 either, but she was there for the humor. They wouldn't add them last season because it was plot based, shes too silly to be in a plot based season, but now that we're in a humor based one, its possible she'll return.