It was not a bad effort considering she admitted her farming knowledge and skill was "pretty basic" prior to moving to the Maniototo in August last year to work for the Hore family at Stonehenge.
Miss Boardman (20), who grew up in Oamaru, said she and fellow worker Cam Gray were encouraged to enter by Jim Hore.
"We didn't really have a choice, actually," she laughed.
Since starting work at Stonehenge, she had been learning about merino sheep on a daily basis and Mr Hore also outlined what the competition would involve.
"Other than that, he just teaches whenever we're around the sheep, on the job."
The competition, open to young people aged between 15 and 25, was held recently at the Paterson family's property, Armidale, at Gimmerburn.
It was the first stock-judging competition Miss Boardman had entered and she admitted she was "pretty nervous".
Competitors had about 15 minutes to inspect four merino rams.
They then had to write down the good and bad points of each, rank them in order and then give an oral presentation justifying their placings.
Miss Boardman, who placed the four sheep correctly, said she had "no idea" if she had them in the right order.
Having assessed each ram's conformation, wool quality and overall presence, she was hoping to at least get a placing and she was "overwhelmed" to be named the winner.
"I don't know who was happier - me or Jim [Hore]", she laughed.
Miss Boardman and Ben Butterick, who works for the Calder family at Lauder Station, will now represent Central Otago at a junior judging competition at the Canterbury A and P Show in Christchurch in November.
The winner of that event will win a trip to Australia.
Mr Butterick was second in the Central Otago competition, while Andrew Jopp, of Moutere Station, was third.
Organiser Simon Paterson said the standard of entries was high and it augured well for Christchurch.
Miss Boardman was looking forward to the prospect of attending Christchurch show, which she had never been to, and was planning to do some preparation for the competition.
"I'm looking forward to it, I'm excited about it," she said.
She enjoyed working with merino sheep and learning about them - "I like learning about the wool ... and what you can do with it" - and she also enjoyed the genetics side of stud breeding.
Miss Boardman loved her job and said her future career path would include "something to do with farming".
"It'll always be a big part of my life."
She is secretary of the Maniototo Young Farmers Club, which has more than 20 members, and enjoys club meetings, activities and events. A recent ball attracted about 140 people.