[1] Dewes was born and raised in Suva, Fiji[2] of mixed Rotoman, Tongan, Tuvaluan, and Tokelauan ethnicity, and affiliates to the Māori iwi Ngāti Porou.

[1] She gained a doctoral degree from the University of Auckland with a thesis entitled Obesity Prevention in Pacific Adolescents: Is there a role for the church?

She later joined the Maurice Wilkins Centre for Molecular Biodiscovery as an Associate Investigator, and is a Research Fellow at the University of Auckland's Centre of Methods and Policy Application in the Social Sciences.

[1] Her research is focussed on the Pasifika community in New Zealand, studying family caring, ageing, chronic diseases such as obesity and Type 2 diabetes,[3] and the role of the church in promoting well-being.

[1] Dewes was appointed a Member of the New Zealand Order of Merit in the 2023 for services to health and the Pacific community.