i know you probably didnt ask for it but some ideas : you could make Sophia have a personal conflict? you could add in how her family neglecting her effected her? you could add in a small love triangle ( a student from beuxbatons or another school participating in the triwizard ), the other person bringing out harrys insecurities? you could have sophia interact with a slytherin ( or any other house , i just chose slytherin cuz the weasleys dont like them )