[7] Harrison was first selected for the Black Sticks Women in June 2009, along with ten other players as the Black Sticks squad was overhauled following its last-place finish at the 2008 Beijing Olympics,[10] joining her older sister Charlotte, who had been in the team since October 2005.

[5] Harrison was part of the New Zealand team that played at the 2010 Commonwealth Games, winning a silver medal.

[12] At the time, Harrison spent three months in Cambridge, England, coaching hockey at The Leys School.

[13] At the 2018 Commonwealth Games, Harrison was part of the New Zealand team that won the women's competition.

[11] Despite Samantha being two years younger and three centimetres (1 in) taller than her sister Charlotte, once the two competed together for the Black Sticks, their similarities in appearance became apparent and they were often mistaken for each other by commentators and match officials.