"Best birthday present ever."
Watkin's goal after first making the Central Districts Hinds as a youngster in 2013 was to try and break into the White Ferns before she finished Whanganui High School.
Playing against men in the local Tasman Tanning Premier 1 club scene for St John's Tech, Watkin came close to that goal when she was chosen for New Zealand A at the end of 2015, while she was also selected for the New Zealand Under 18 and Under 21 indoor cricket teams to attend world tournaments in 2015 and last year.
She has been a fixture in the Hinds, winning the province's player of the year award in 2016-17 and two sub category awards this year, while captaining the CD Under 21 team to the national title with a dominant tournament in December – topping the overall batting and bowling charts.
Having left high school, Watkin opted to remain in Whanganui while studying extramural at Massey University, so she could keep up her current training routines in the hope of reaching the White Ferns standard.
"My [on-field] performances have helped. My fitness – I've been working really hard over the past four months."
Watkin thanked trainer Ebony Kerr for her efforts, and especially Cricket Wanganui guru Dilan Raj.
"I've worked with Dilan since I was 11, so he's been a big part of it."
The news was a delight to her parents and grandparents, as well as older brother Kane Watkin, a former Wanganui Men's senior representative.
"As much as he hates it that I'm better than him, he's still pretty proud," she laughed.
As the newcomer to a settled team, captained by Suzie Bates, Watkin is not expecting too much game time, but is eager to watch and learn while seeing how she goes on Northern Hemisphere pitches.
Arriving in Dublin on June 1 and playing six days later, the White Ferns take on Ireland in a Twenty20 match and three One Day Internationals (ODI), then will enter a T20 Tri-series against South Africa and England, followed by three ODI's with England, who are the reigning world champions.
"I haven't really watched [Ireland, South Africa] because it's not televised live," Watkin said.
"I watched the English girls when they were here and they've got some big stars."
White Ferns selector Kirsty Bond said Watkin is a special player who they have been keeping an eye on since 2013.
"She's an explosive batter who hits the ball hard and is a more than useful off-spin option, so she offers us great versatility.
"We've also been impressed by the work she's done on her fitness and physical conditioning over the past season."