The former head girl of Waikato Diocesan took up the hammer around 12. Her father, Dave, a physical education teacher and now her coach, got Ratcliffe and older sister Sarah into athletics. She joined the Hamilton City Hawks club as a nipper and has been a member since.
She tried hurdles - "which is quite funny looking back" - before being introduced to the hammer.
"I didn't dislike it, but wasn't all that keen on it at the start," she said. "Dad kept saying 'let's go out and give it another go'. I kind of got stuck on it."
As she discovered an aptitude for it, so she derived greater enjoyment from developing a skill which involves swinging a 4kg ball on a 119.5cm line twice above the head, before making three or four rotations of the body and flinging it far.
"It's not something your body does naturally. It's very much a learned movement. I have found it very satisfying over the years to see the hard work and practice has paid off.
"When you see a throw go right, you know everything has fallen into place. It's that kind of reward type payoff that hooks me into it."
Ratcliffe discovered the importance of sport at Princeton at the university track and field nationals in Oregon last month.
For the past 43 years at least one Princeton individual or team has won at least one NCAA title. When Ratcliffe's time came, Princeton's list of winners this year stood at zero.
"So people in the sports department were saying 'you're our last hope'. I tried not to think about it in case I stuffed it up." She didn't.
Princeton is not a school which gifts out soft sports scholarships. Academic standing is important. Ratcliffe, who is studying economics, looked about for American possibilities.
In the end, "we shot for the stars" and, her academic achievements impressive, was accepted. She has successfully completed two years.
"It's very much a work hard, play hard atmosphere and I just love it. So rewarding. The work you're putting in is at a very high level of thinking, academically stimulating, but I don't know if it's sustainable for more than four years."
Working with her Hamilton-based father isn't easy, but the coach and pupil are making a decent fist of it. Ratcliffe works with Princeton coach Brian Mondschein, who implements her father's programme.
"He films me, I look at it and send it back to Dad, then Skype him twice a week. It's not ideal but we're making it through and I'm improving every year."
At the Istvan Gyulai Memorial meet in Budapest last week she finished eighth with a best throw of 68.75m. Her personal best is 70.28m, in April this year.
But she got to compete against the world record holder - at 79.42m - German Betty Heidler and Polish 2009 world champion Anita Wlodarczyk . It's all part of the learning process which Ratcliffe hopes will help her Glasgow performance.
The two Games athletes ranked higher than her will be Canadian Sultana Frizell , the world No 7, and England's Sophie Hichon, world No 23, seven spots higher than Ratcliffe.
Ratcliffe admitted it is hard not to think about medals.
"It really depends how well everyone else does. I can't help it if a girl in fourth pulls out a massive throw.
"I want to throw well for myself, for New Zealand, so I can be proud of my performance, rather than go in with place pressure. The great thing about athletics is it's about who brings it on the day."
