Auntie Usma is the aunt of both cousins Chesney Karib and Sita Desai. In Episode 7 of Series 8 Chesney began to take the Karib's Shop for granted and neglected it's upkeep, Sita warned that Auntie Usma would be sent to work there by their grandfather if she sent word of Chesney's negligence. Chesney showed fear at the idea and a short clip of Usma showing excellent skill with nun chucks to scare shop lifters into returning their items was shown. At the end of the episode Chesney tried to force a hijab (Muslim veil) wearing woman out of the shop, unaware that she was his aunt, Usma made quick use of her apparent martial arts training to hit him with a sweeping brush. She has been seen briefly in other episodes throughout the series, never speaking and never removing her hijab.
Due to her relation to both Chesney and Sita it is possible her last name is either Desai or Karib, but as it is never stated it is impossible to know for sure. Usma never removes her hijab and is never mentioned during the show's credits so it is also unknown who portrays her, due to the full body veil it is possible she is portrayed by someone already acting on the show or various people.