The Queenstown beauty therapist spent 10 days in the capital doing photo shoots, endorsements and public speaking and on Sunday night was named in the top four.
"I'm really proud of myself. I achieved a lot this week and it was a great experience.
"I found a new level of myself and I can only grow from here."
Miss Cooley (22) spent months in preparation, including hours at the gym, speech lessons and saving for her first trip to the capital.
A highlight for the young woman who wants to study psychology was a visit to the Beehive to see parliamentarians debate.
"It was great getting to Parliament and seeing them in action.
"I found that highly interesting ... they're very passionate."
Miss Cooley and her mother, Linda Cooley, will fly to Hawaii tomorrow for a 10-day holiday.
"Relaxing involves sleeping, taking the heels off and wearing no make-up for, like, ever."
While the decision lay with a panel of judges on Sunday night, she said there could have been 10 girls wearing the crown.
"All the girls are winners in my eyes, with how hard we worked."
Miss Howick, Avianca Bohm, was named Miss Universe New Zealand 2012.
Miss Cooley said she would consider representing the region again next year.
