Mrs Smith was the mother of Mike Smith. Living in the Shoreditch area, she ran a boarding house where the Seventh Doctor and Ace stayed during the Shoreditch Incident in November 1963.
Her son Mike was killed when he confronted Ace back in the boarding house. He answered a knock at the door and was killed by the Girl. Mrs Smith attended her son's funeral with Group Captain Gilmore.
Ace suspected Mrs Smith of having prejudiced views after Ace found a sign hanging in her living room window reading "NO COLOUREDS". (TV: Remembrance of the Daleks)