The bubbly St Kevins College pupil won the Otago-Southland secondary school championships, finished second in the South Island secondary schools event and was third in the New Zealand secondary school championships.
Late last month she was named in the Triathlon New Zealand youth academy and looks to have a bright future.
It has been a remarkable six months and it has all been achieved on a smile.
Before this year the Academy Otago inductee raced for fun and did not take the sport too seriously.
"Last year and the year before I only did them for fun. This year it has got serious. I've got a coach and everything," she giggled.
Reubyn (16) was awakened to the possibilities while at a triathlete camp in Christchurch.
"[Andrea Hewitt] spoke and it was quite inspiring."
Hewitt won her second World Cup event in Madrid this month when she pipped Swede Lisa Norden by a fraction of a second in a dramatic sprint finish.
It was the sort of performance which should help Reubyn to stick to her new regime in the pool.
She is a good cyclist and a strong runner, but Reubyn is tired of getting out of the water towards the back of the field and is determined to improve her swim leg.
"I've never been a swimmer. They always say runners can't swim but I'm getting there this year. This winter I'm going to get stuck in at the pool."
That means four or five sessions in the pool each week which, on top of all the cycling and running, does not leave time for much of anything else.
"It is kind of hard juggling training and study. I'm either biking or running or at the gym.
"I try to make time for my friends in the weekend but you don't want to stay up too late with training the next morning."
Reubyn's father is a keen runner and she got her start training alongside former Otago distance runner Adair Craik at a small club in Oamaru.
Her next big event is the New Zealand secondary schools duathlon championships in Palmerston in August.
It is run-bike-run event. No swimming - which should suit Reubyn.
Next year Reubyn wants to win the New Zealand secondary schools championships and is eying up selection for the World Youth Games.
