Undheim published a monograph with Routledge in 2018, Borderline Virginities: Sacred and Secular Virgins in Late Antiquity.[3] She edited a collection of translated texts on Roman religion (Romersk religion) for the Norwegian series Verdens Hellige Skrifter (Sacred Texts of the World), published in 2010.[4] With Marie von der Lippe, she edited the volume Religion i skolen: Didaktiske perspektiver på religions- og livssynsfaget, published in 2017.[5]
Undheim was a Fellow at the Centre for Advanced Study at the University of Oslo, 2020–21, for the project 'Books Known Only by Title: Exploring the Gendered Structures of First Millennium Imagined Libraries'.[6]
