Cowley (28), a fulltime athlete from Auckland, won four senior titles when the event was held in Dunedin in 2001. She won the high jump, long jump, 100m hurdles and the 4x100m relay.
"It was a great weekend for my final secondary school nationals and coming home with four titles," Cowley said.
"It was the first time I jumped over 6m in the long jump, which was a great feeling."
Cowley was a promising athlete at school and finished ninth in the 4x100m relay at the world junior championships in Santiago in 2000, and fifth in the medley relay at the world youth championships in Debrecen in 2001.
She has concentrated on the heptathlon for the last seven years, finishing 10th at the Commonwealth Games in Melbourne in 2006, and 26th at the Olympic Games at London this year.
"Competing in London was phenomenal," Cowley said.
"Being on the world's greatest sporting stage was what I was after for a long time.
"It was very noisy in the main stadium and having three Brits and the "Face of the Games" [Jessica Ennis] in my event made the heptathlon special. It was a great feeling throwing a personal best of 41.90m in the javelin.
"I wanted more but it was my second-best legal points score so I can't complain too much."
It took Cowley 11 years to go from the national secondary schools championships in Dunedin to the Olympics in London.
She has the second-best all-time score of 6135 points for a New Zealand athlete in the heptathlon and the second-best high jump of 1.91m.
The New Zealand secondary schools championships will be held at the Caledonian Ground on December 8 and 9. It will be the fourth time the event has been held in Dunedin. The other occasions were in 1985, 1991 and 2001.
