She was a member of the New Zealand teams that won gold medals at the 2003 World Netball Championships and 2006 and 2010 Commonwealth Games.

In 2023, Harrison was appointed a Member of the New Zealand Order of Merit, for services to netball and volleyball.

[24][25][26][27] She was subsequently a member of the 2011 Northern Mystics team that finished as ANZ Championship grand finalists.

[29][30] On 20 May 2012 while playing for Mystics in a 2012 ANZ Championship Round 8 match against Melbourne Vixens, Harrison made several vital blocks while being hoisted rugby union lineout-style by her defensive partners.

Cullen and Moulds adopted the role of a lineout lifter to hoist Harrison and the move had the desired result in the final quarter when Vixens goal shooter Karyn Howarth's goal-bound shots were twice batted away.

[9][46][47] On 1 August 2018, she made her last appearance for Mystics in a 2018 ANZ Premiership Round 13 match against Central Pulse.

[45][48][49][50] In 2021 and 2022, after coming out of retirement, Harrison made 28 senior appearances for Northern Stars in the ANZ Premiership.

[18][57][58] On 7 May 2022, while playing for Stars, Harrison made her 150th senior league appearance in a 2022 Round 9 match against Waikato Bay of Plenty Magic.

[3][69][62][71] She was subsequently a member of the New Zealand teams that won the gold medal at both the 2003 World Netball Championships.

[97][98] Sources:[23][53] Between 2008 and 2010, together with Susan Blundell, Scarlett represented New Zealand on the FIVB Beach Volleyball World Tour.

[125] During her beach volleyball career, Scarlett spoke out about how "a skilful game" is marketed as "women running around in bikinis.

She was a member of their commentary team for the 2019 and 2020 ANZ Premiership seasons and for the 2019 Netball World Cup before coming out of retirement to play for Northern Stars.

[51][129][130][131][132][133] In the 2023 New Year Honours, Harrison was appointed a Member of the New Zealand Order of Merit, for services to netball and volleyball.

Together with Leigh Gibbs and Kereyn Smith, she was one of several New Zealand netball people to receive an honour.

[1][10][11][134] On 13 April 2023 she attended an investiture ceremony at Government House, Auckland where she was presented with the honour by the former Governor-General of New Zealand, Sir Anand Satyanand.