Series 3, episode 1.
As someone who was unfortunate to know Sophie Wu at school, I can confirm this "autobiographical" piece of work is total rubbish. Sophie herself tormented several people at the school she was allegedly expelled from and continued to do the same at her new one. Not only that, she hasn't even bothered to change the surname of one of the characters, something she could easily get sued for.
Sophie was, however, exactly the same as Franny Wong in the sense that she was a creepy try-hard with no self-awareness, who took no responsibility for anything she said or did. I'm amazed BBC3 even commissioned this, to be honest.