The 26-year-old, who switched from pop opera to pop two years ago, is not shy about sharing her views.
As well as having an active Twitter profile, the Rotorua native launched Villainesse last year, an online media venture aimed at young women.
Its first major project was #MyBodyMyTerms, a global campaign to spark conversation about sexual violence, victim-blaming, revenge porn and consent.
"I'm devastated by what's happening around the country, obviously, but I'm so heartened by the fact that we're talking about it ... I certainly don't expect to change the world in a day, but I think if you keep soldiering on then things start to change."
She writes from a feminist point of view, but that "really just means a firm belief in equality", Marvelly said.
"The framing that's applied to some stories, especially about young women, is concerning to me. To be able to examine some of that is something I'm really looking forward to."
Sex ed in schools, the flag referendum and child poverty are also likely to come under the microscope.
An ambassador for the children's charity Variety, Marvelly is frustrated by failures to recognise poverty can stand in the way of success. She said the community had to work together on solutions.
"That blame on lower socio-economic communities is repulsive and the way it reflects on our society is that we don't care, and I care, massively. I go to these lower-decile schools with these beautiful kids and they just want to learn and play and be the awesome little humans that they are, but they can't because they're hungry."
In between all of this, Marvelly, who has produced two albums, will be making music.
Last year, she collaborated with hip-hop DJ and producer Peter "P-Money" Wadams on the single Made for You. There's more to come.
"Musically, I've been taking time writing music I want to write. I really feel like now I'm coming to a place where I know what I want to say."
