Kelsey Hooper

Kelsey Hooper was the first schoolmate that Maria Jackson met on Bannerman Road.

Biography
As a child in 2008, Kelsey approached the Jacksons and became Maria's first friend when she noticed the moving vans on Bannerman Road. Almost immediately, she suggested they go into town on the free Bubble Shock! bus; the bus made a mandatory stop at the Bubble Shock! factory, where she and Maria met the Archetype. Kelsey was briefly held prisoner by Mrs Wormwood and used for her knowledge of Sarah Jane Smith. After leaving the factory, she warned Sarah about an attack from Davey and discovered Mr Smith in the attic.

Maria later described Kelsey as "backtracking like mad — saying there's no such thing as aliens". (TV: Invasion of the Bane) They were still friends when Maria met Uvlavad Kudlak. (PROSE: Warriors of Kudlak)

Notably, a woman sharing her name and broad visual appearance later joined Faction Paradox in the War in Heaven, taking on the name of Cousin Ceol. (PROSE: Now or Thereabouts, Weapons Grade Snake Oil, etc.)

Behind the scenes

 * After the pilot episode of The Sarah Jane Adventures, Invasion of the Bane, the decision was made for the character to not return; no explanation was given by the BBC. Kelsey's role in the series was filled by Clyde Langer.
 * The recurring Faction Paradox character Ceol was transparently intended to be an older version of this Kelsey. However, there is no indisputable narrative evidence of their shared identity, nor much in the way of real world evidence that Obverse Books sought a license to continue the televised Kelsey's story from Russell T Davies or the BBC.