She specialises in the study of Greek, Roman and Punic coinage, in particular examining their role in historical processes and as social agents.

[1][2] She has worked on a number of numismatic and archaeological projects, including as a project manager for the archaeological service of the Canton of Bern, at the site and museum of Aventicum, and from 2003 to work on the coinage of Monte Iato in Sicily, funded by the Swiss National Fund for the Promotion of Scientific Research (SNSF).

[3][2] She has held two Visiting Professorships: first in 2014, at the American Numismatic Society; secondly in 2017, at the Università degli Studi.

[2] Her research interests include the study of Greek, Roman and Punic coinage, and, in particular, coins in archaeological contexts, as well as their role in historical processes and as social agents.

[2] According to Carolina López-Ruiz, Frey-Kupper's work on coinage at Punic sites emphasised the "importance of paying attention to local contexts", but these contexts do not "undermine the existence of a level of uniformity".