The Year Two student at Li Po Chun United World College, in Wu Kai Sha, Sha Tin, is one of the organisers of next month's Hong Kong 24-hour charity race, Running to Stop the Traffik.
The team event, which will feature up to 400 runners from 15international colleges, aims to raise up to HK$500,000 to help rescue Nepalese children that have been sold to work in India.
Mary, 17, was inspired to organise the race by former student Christopher Schrader, who left the college at the end of last term.
Chris founded the Youth Endurance Network to encourage young people to help others through sport. He organised a similar 24-hour charity race last year. "It was because of him that I wanted to help organise next month's race," Mary says. "I took part in the last Running to Stop the Traffik event."
Mary's race, which starts on November 26 and finishes on November 27, will - like last year - be held at Victoria Peak. Teams must always have at least one member running laps of the course during the 24 hours.
All proceeds will go to the Esther Benjamins Trust, British-based charity that rescues Nepalese children who have been sold to work in India, sometimes to perform in circuses. The charity helps provide children with full-time residential care, education and training, and also supports other Nepalese schools.
Mary says: "We have relatives, friends and schoolmates promising to donate a fixed amount for every lap we finish in 24hours, so it is also important to run as many laps as possible.
"We hope to raise a total of HK$500,000 - about HK$300,000 from sponsorship of individual runners and HK$200,000 from business sponsorship.
"I am confident that our Li Po Chun's girls' team can run more laps than last year and can raise even more money." says Mary, who is part of the race's organising committee.
A second 24-hour charity race will take place at the same time in Singapore. "Together with students from Singapore, we will be organising a live Tweet-cast on Twitter for both races," Mary says. "Spreading the race and it's message around the world is really meaningful."
She became interested in running when she was a Primary Four student. "For the first time I entered the 800m final at my school's athletics meeting. I wanted to perform well so I went for some practice runs with my dad," Mary says. "I came fourth and didn't win a medal, but it was a turning point in my life."
Mary was soon training alongside other athletes and her running improved. Later she transferred from South Island School to Li Po Chun UWC to finish her final two years of high school. Although the school workload was heavier she continued to train and improve as a runner.
"Our Wu Kai Sha campus faces the mountain and sea. It is easy for me to run on the road and mountain trails," she says. "I can always run around the school so it means I don't have to spend lots of time travelling to places to train."
Her rigorous training has helped her win numerous prizes. Last month she was second in the 10km "Coca-Cola Running Fun" race at Wu Kai Sha Youth Village, near Ma On Shan. "The best thing was I ran three minutes faster than last year."
Mary is very disciplined as a runner - using a different training schedule each day - including speed-interval running, jogging and yoga - to stay fit and healthy. "I get up at 5.45am in the hostel and go for a short jog before lessons, so I go to sleep at about 10pm everyday," she says. "It is pretty early to get up then, yes - but endurance sport is what I love to do. I don't feel it's difficult to do it. I like taking on challenges."
She had plans to organise a 24-hour, 150km ultra-marathon for girls in aid of charity from Wu Kai Sha to Repulse Bay. It would have involved long-distance swimming, running and kayaking. But her doctor warned her that such a gruelling event would be too exhausting - even for her. "It has been cancelled because of the possible health risks," Mary says. "But I will think about organising something else to raise money for charity later on, for sure."
For more information on the Youth Endurance Network, visit their website at www.youthendurance.com/news1.html