Najia was born in Sheffield to Umbreen and her second husband. She was of Pakistani Muslim heritage. (TV: Demons of the Punjab) She married Hakim Khan and had two daughters: Yaz and Sonya, living together in Flat 34 of the Park Hill estate in Sheffield. (TV: Arachnids in the UK) She told Yaz that she carried her father in her heart after he died. (PROSE: The Good Doctor)
In 2018, Najia was hired as general manager of Jack Robertson's Sheffield hotel. She was swiftly fired due to the poor state of the hotel rooms thanks to a giant spider outbreak. Embarrassed, she called Yaz to pick her up and was threatened at gunpoint by Kevin for trespassing. Standing up for her mother, Yaz asked why she'd been sacked and Najia and Yaz were shown the state of one room full of cobwebs that no one could explain.
Najia met the Thirteenth Doctor, Ryan Sinclair, Graham O'Brien and Dr Jade McIntyre at the hotel after they found the link between the hotel and the giant spider outbreak. Najia seemed somewhat concerned at the Doctor's presence and believed that she and Yaz were in a relationship before the latter clarified they were friends. Yaz slipped away to travel in the Doctor's TARDIS whilst Najia thought that she was getting bread. (TV: Arachnids in the UK)
She celebrated her mother's birthday at Flat 34. Umbreen complained about the shop-bought cake, but Najia insisted the cake was good. Najia also received the letters that her father sent Umbreen while he was away and was cautioned not to read the "filthy bits". (TV: Demons of the Punjab)