Now three years on, the Year 13 student at John Paul College in Rotorua has matured and is looking to put her experience into practice.
Grigsby said competing at an international level was a different experience to any other climbing competitions she had attended.
"The talent of some of these climbers is mind-blowing. It's exciting to watch and learn from these climbers in the flesh.
"Having competed at an international level before will help me enormously in New Caledonia. It will help me relax on the wall and be more focused when competing."
Chris Gatland, the president of the Auckland Climbing Club, believes that if Grigsby climbs to her potential she should be in contention.
"Rotorua has one of the strongest clubs in New Zealand and Aiyana is a regular on the podium at the national competitions," he said.
"She has an excellent chance of reaching the semifinals in her category."
Grigsby has shown plenty of ability at a young age and she has already enjoyed success at the worlds venue. She finished third in the Oceania Championships for rock climbing in New Caledonia.
She said the wall they are competing on in New Caledonia is vastly different to any in New Zealand.
"It is an outdoor wall in the direct heat so we will be competing in temperatures much warmer than we're accustomed to. The environment poses an awesome challenge for us."
Grigsby's favourite climb in New Zealand is The Wall and Basement Cinema in Rotorua. The Wall is the tallest climbing gym in the country (18m high) and she considers it her second home.
To prepare for the Youth Worlds, Grigsby has been training at least six times a week. She trains three or four times a week on the wall, then mixes it up with cross training, running, and time in the gym.
"The wall in Noumea is so tall, my focus has been on my endurance so I can last longer on the wall."
More often than not Grigsby's biggest problem is resisting the urge to over-train.
"I will often train until there is no skin left on the inside of my hands. Climbers' hands are never pretty, and years of squishing my feet inside undersized shoes will render my chances of being a foot model highly unlikely, but the 'high' of climbing keeps me on the wall."
She began climbing when she was 11 after growing up in gymnastics and credits coach Lossie Maafu for her rapid rise in the national ranks. Now she hopes to take on the world.
"Competing against the best climbers in the world is an awesome feeling. It is super exciting that I will be able to watch them climb the same climbs that I will be doing. Many of the climbers at this event hold impressive European titles, so are hugely inspirational."
It is all a long way from where it began for the teenager. Grigsby recommended any young athletes interested in climbing to get to a local climbing gym and give the sport a go.
"Climbers around the country are notoriously friendly and encouraging. First time competitors are often astounded by the friendliness of the climbing community. My local club [Rotorua Climbing Club] has been paramount to my success, and they continue to support me in my fundraising efforts for this competition."
Four hot tips: Four things Aiyana Grigsby has learned as a rock climber
• Armpits make perfect shoe warmers
• To avoid a frisking, package climbing chalk carefully when going through customs
• Nail clippers are a girl's best friend
• Never eat near climbing shoes (even your own!)
