"It was kinda scary. We'd trained for this for almost three years and it came up quickly. But it's always been my aim to get to this level where I am now," says the midfielder, who provides the crucial link between attack and defence.
Thursday nights in winter feature school lacrosse matches, while on Sundays, mainly through the summer - though the sport can be played all year round - she turns out, along with Barker, for the strong Harbour Hawks top club side.
"I'm more mature now playing with them, so it hasn't been an issue. It's helped me," says Archer, on playing with and against seasoned lacrosse exponents.
The focus for the rest of the year will be on training and raising the considerable amount of money required to get to Scotland. Lacrosse receives little in the way of funding.
"It hasn't really hit me that I'm representing New Zealand because lacrosse is not a big sport. It's quite crazy. Some have heard of it but they don't get it or understand it," Archer said.
Her teammate Barker, a defender, does get it. She has played the sport since Year 9, but only got serious two years ago.
"It came really suddenly for me because I didn't know about this New Zealand team. I saw there were trials for the World Cup squad in July 2013. I thought I'd give it a crack," Barker said.
That led to a 2014 tour of Australia, which whetted their appetite for international play.
She says New Zealand has ambitions for a top eight finish in Edinburgh, after placing 12th four years ago in Germany.
Barker explains her love of lacrosse: "It's just such a different sport. It's contact and it's so different to be able to throw the ball to each other with sticks rather than passing with your hands."
Whangaparaoa has fostered a strong lacrosse culture, though 2014 was a messy season, with several matches cancelled due to poor weather or other schools defaulting. The school is seeking a new coach for the 2015 season, starting in May.
"Our school has always had a couple of players who have been in that under-19 training environment, so there's always been players to get advice from and feed knowledge off," Barker said.
Neither Barker nor Archer will have far to go for advice when they compete on the other side of the world in five months.