Last name Guðmunda (Guðmunda ) , globally, is an extremely rare cognomen. Much more frequently, Guðmunda is the forename as well as the last name.
Smáradóttir, Steingrímsdóttir, Sigurðardóttir, Finnbogadóttir, Júlíusdóttir, Guðmundsdóttir, Jóhannsdóttir, Gísladóttir, Matthíasdóttir, Jónasdóttir, Birgisdóttir, Magnúsdóttir, Helgadóttir, Emilsdóttir, Jónsdóttir, Gestsdóttir, Kristinsdóttir, and Kristjánsdóttir