Misjudged follows a child's struggle to meet an expectation she is not sufficiently grown up for, and is based on her own childhood experiences.
Ms Helean, a health planner for the Auckland District Health Board, has been writing for many years.
She said it was her master's degree in creative writing from Auckland University - and her mentor Witi Ihimaera - that really gave her the springboard to launch into serious writing.
"I always loved writing, especially bringing the imaginary world to life," she said.
In her job with the health board, she is immersed in writing, but she described it as deeply bureaucratic.
"I write reports, strategy and planning documents by day, and by night I flip into creative overdrive," she said.
And while the two disciplines were markedly different, they did complement each other.
Just being used to writing all day, every day was a big help, she said.
"There's some dexterity needed to get large documents through to completion.
"You need a certain fluidity in writing, perseverance and staying relaxed around chaos."
Ms Helean received the award and $10,000 at a ceremony in Wellington yesterday.
Other award winners were: Novice writer: Nicole Tan (Auckland); young writer: Emily Hunter (Hamilton); short story: Chelsea Dempsey (Wanganui).
