The issue of multiple marginalisation appears as a theme in one form or other in all of Lumberg’s works. Following her screenplay for a television mini-series ‘Tumma ja hehkuva veri’ [Dark and Glowing Blood], 1997, which was the Finnish entry for the Prix Italia 1998 and was also reworked into a theatre play, and some appearances on TV, she received harsh criticism and threats from some members of the Finnish Romani community.
In the first decade of the twenty-first century, she published three semi-autobiographical novels: Musta perhonen [The Black Butterfly] (2004), Repaleiset siivet [Tattered Wings] (2006) and Samettioyö [The Velvet Night] (2008), later compiled into one volume as Memesa-trilogia [Memesa Trilogy] (2011). The novels follow the heroine from her early childhood into adulthood. They manifest generic features of literature for girls, but also of a feminist type; a lesbian/queer Bildungsroman, a female Künstlerroman (artist’s novel), auto-fiction and feminist ethno-autobiography.
Lumberg has published two comic books (Gipsy comix! and Hullun taiteilijan päiväkirja [Diary of a Mad Artist], both in 2010, in her Aurinkogalleria, an art gallery, publishing house and a place to meet and discuss and promote alternative forms of art. Lumberg has authored several video works (e. g. Gräi-Hevonen [Horse], 1990) and she has staged various socially committed performances, courses, workshops and art exhibitions in Finland and abroad, sometimes in the role of exhibition curator and producer as, for example, in an international exhibition of contemporary art by Romani women. Notable is her participation in the Venice Biennale: at the first Roma Pavilion in 2007 and at the Roma Pavilion project “Call the Witness” in 2011.
In her art and activism, which includes the founding of the art group Tulikaste and standing as a candidate in the 2007 Finnish parliamentary elections on behalf of the Left Alliance, she combines a critical view of all social groups with campaigning for human rights and environmental protection as well as equality and social justice inside and outside her own community.