Shareen Costello

Shareen was a friend of Rose Tyler's. (TV: The End of the World, The Unquiet Dead, School Reunion)

Rose typically went to parties with Mickey Smith and Shareen. (PROSE: Rose and the Snow Window) According to Rose, Shareen would always say, "Don't argue with the designated driver". Rose quoted this statement after journeying with the Ninth Doctor to Platform One in the year 5.5/Apple/26. (TV: The End of the World)

Rose recalled another saying of Shareen's, "Worry about that tomorrow", while thinking about her desire to keep the Doctor secret from her boyfriend Mickey. (PROSE: Rose)

Biography
When Rose and Shareen were ten, they planned to sneak out to Danny Fennel's party and pinched a bottle of wine from Jackie's kitchen cupboard to get them in the mood. After a glass each they fell asleep, missed the party and got scolded by Jackie. (PROSE: The Stone Rose)

When Rose was in school, she would often intentionally miss class to go shopping with Shareen, and the two girls would go to look at boys. (TV: The Unquiet Dead)

On their school trip to Paris, they never got to see the Mona Lisa because Rose and Shareen went to Parc Asterix instead. (COMIC: Art Attack)

Before Rose left her home planet of Earth with the Ninth Doctor on 6 March 2005, Shareen had been upset and Rose had tried to comfort her, spending at least one night at Shareen's in her effort to do so. (TV: Aliens of London)

After Rose returned to Earth with the Ninth Doctor, she told him that she planned to explain her twelve hours' absence from the council flat she lived in with her mother Jackie, by telling her mother that she had spent the night at Shareen's. When she went back to her home, Rose claimed that Shareen had been "all upset again". However, as Rose had actually been away for twelve months, and not the twelve hours that the Doctor had erroneously estimated, Jackie knew better than to believe her story about having been at Shareen's. (TV: Aliens of London)

After an argument with Sarah Jane Smith, Rose cited that the only time she and Shareen "fell out" was over a man, while she and Sarah Jane were similarly fighting over the Tenth Doctor. (TV: School Reunion)

Behind the scenes

 * Shareen has never appeared on Doctor Who, and has only ever been mentioned by Rose.
 * In the Doctor Who Annual 2006, an article about Rose, written by Russell T Davies, includes a paragraph that gives Shareen's last name as "Costello". The paragraph details how, on a school trip to France when Rose was 13, she and Shareen, Rose's "best mate" (at least at that time), escaped the teachers who were accompanying them, crossed town, and boarded a train to Parc Asterix, instead of going to the Louvre (which they had been scheduled to visit on that day). After they were caught by police while waiting in a queue for the Menhir Express, Shareen was sent home with Rose. These events were later mentioned by Rose herself in COMIC: Art Attack.