Julia Swales
Julia Swales was a friend of Martha Jones and a trainee medical student at the Royal Hope Hospital in London. (TV: Smith and Jones, PROSE: Martha Jones' MySpace blog)
Three days before Martha first met the Tenth Doctor, Julia's engagement with her fiancé Steve came to an end, and she relied on Martha for emotional support. Like Martha, she was a Harry Potter fan. (PROSE: Martha Jones' MySpace blog)
Julia was one of the people trapped in the hospital when it was transported to the Moon by the Judoon. That day on her morning rounds, she saw the Tenth Doctor and Florence Finnegan. She recommended ordering a CT scan or blood tests for Finnegan, but Dr. Stoker said that would be a waste of money and that the patient was simply salt-deficient. During the subsequent ordeal, Julia was terrified throughout, but she continued caring for her patients helping make sure that they got oxygen. She was the last to succumb to oxygen starvation but still managed to survive the crisis. (TV: Smith and Jones)
She was still friends with Martha a year later, when she was working on the CERN machine in Switzerland. She warned Martha that there were problems before being kidnapped. She was later rescued by Martha, Jack Harkness, Gwen Cooper and Ianto Jones. (AUDIO: Lost Souls)