Hessell completed a master's degree at Victoria University of Wellington in 2000, with a thesis titled Invention and re-invention: the composition of Mary Robinson's Lyrical tales (1800).
[3] Hessell then joined the faculty of the Victoria University of Wellington, rising to full professor in 2022, where she is part of the New Zealand India Research Institute.
[6] Alongside co-author Stephen Clothier, Hessell won the International Association for the Study of Scottish Literatures' inaugural Jack Medal in 2018.
The prize is awarded annually for the best newly published academic article on a subject dealing with Scottish literature and related to reception and/or diaspora, and Hessell and Clothier won for the article To Mary in Aotearoa: Burns’s ‘Thou Ling’ring Star’ and Scottish Identity in New Zealand.
The judges commented that "Hessell and Clothier's consideration of Robert Burns's reception in New Zealand opens up important discussions about diaspora, indigeneity, and literary interpretation in Scottish studies".