Sian is the first person in the country to study the subject at GCSE level, and was given special permission to nominate it as her sport for her PE exam - kids usually take football, rugby, athletics or swimming for the practical element of their course.
Skydiving is something of a family affair for Sian whose dad Sandy is the former UK skydiving gold medalist and coach to the Red Devils display team.
Sian took her first indoor skydiving lesson at 12, and has been addicted ever since, practising at an indoor centre every week.
She said: "My friends are doing things like swimming for their PE exams and they know that I'm into skydiving, so it's not such a shock for them that I want to do this."
Sian's practical assessment will count for 60 per cent of her PE exam, which she is taking alongside more conventional science, drama, history, geography, maths and English exams.
Sian says her parents and granny are to blame for her love of the sport, and says that her interest has 'just gone from there'.
Her proud dad says she is 'nervous, calm and excited' about the exam, and added that he wished he could have done it when he was at school!
Amazing! Let's hope Sian gets an A*!