Julia Swales

Julia Swales was a friend of Martha Jones and a trainee medical student at the Royal Hope Hospital in London in 2008. She saw the Tenth Doctor and Florence Finnegan on her morning rounds. 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. Julia was one of the people trapped in the hospital when it was transported to the Moon by the Judoon. She was terrified throughout much of the ordeal, but 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)

Alternate timeline
In an alternate timeline where Donna Noble never met the Doctor, who died defeating the Racnoss, the Royal Hope was still stolen by the Judoon and transported to the Moon. Sarah Jane Smith and her friends were the ones who stopped the Plasmavore and the MRI, but the oxygen ran out before the hospital was returned, causing everyone inside to die from asphyxiation. This would have included Julia. (TV: Turn Left)