Lavinia Smith

Dr. Lavinia Smith was a world-renowned virologist and the aunt of Sarah Jane Smith. Sarah posed as her aunt while investigating the disappearances of scientists, a ploy easily caught by the Doctor, who knew her to be too young to have written a paper on the teleological response of the virus in 1960, as her aunt had done ("The Time Warrior").

In 1978, Dr. Smith was still living in South Croydon when she received a mysterious crate addressed to her niece. Not knowing what it contained, she packed it away and later took it with her when she moved to Moreton Harwood the followng year. Just prior to leaving for a lecture tour of America in December of 1981, she had the crate brought down from the attic for Sarah Jane to open when she arrived a few days later. The crate turned out to be from the Doctor, and the crate contained K-9 Mark III ("A Girl's Best Friend").

Lavinia had a ward called Brendan Richards.