Susan Foreman played by Carole Ann Ford
Susan has been travelling with the Doctor since he left Gallifrey. She often referred to the Doctor as 'grandfather', although it is not known if she really was his granddaughter.
She was resident in the TARDIS with the Doctor whilst she was a student at Coal Hill School; her unusual behaviour piqued the interest of two of her teachers which led them to 76 Totters Lane. She was the first member of the TARDIS crew to depart.