Gasson is currently a member of the Coast Swimming Club as part of their Elite Team training out of Northern Arena in the north of Auckland.
In 2013, she won a silver medal in the 200 metre butterfly event at the New Zealand Open Championships.
[1] At the 2016 New Zealand open swimming championships she broke the national record in the women's 100 metre butterfly in her heat, reaching the qualification standard for the 2016 Summer Olympics in the process.
[1] On 15 April 2016 Gasson was named as one of five Olympic debutants in a squad of eight swimmers to represent New Zealand at the 2016 Summer Olympics in Rio de Janeiro, Brazil, where she competed in the women's 100 metre butterfly and women's 200 metre butterfly.
In 2018 Gasson represented New Zealand again at the Commonwealth Games competing in the 50, 100 and 200 butterfly, as well as the 4 x 100 Medley and 4 x 100 Freestyle relay teams.