Ylvi lives in the Viking village of Flake as Vicky's neighbor. She is his most ardent supporter across adaptations, consistently defending him against less accepting village children. In some interpretations, particularly the German live-action film, her admiration carries undertones of a childhood crush. Ylvi actively joins Vicky and the Viking crew on adventures. Like Vicky once did, she attempts to stow away in a barrel to join voyages, though she is discovered before departure in the original animated series. She shares significant adventures with Vicky in the live-action films. During the raid on Flake in the 2009 film, both are kidnapped and require rescue. Later, in the 2011 sequel "Vicky and the Treasure of the Gods," she aids the quest for the Norse gods' treasure. Similarly, in the 2019 CGI film "Vic the Viking and the Magic Sword," Ylvi stows away with Vicky on the journey to break a curse involving a magic sword and the Bifrost bridge. Within the Studio 100 CGI reboot series, Ylvi is explicitly defined as Vicky's cousin and shares his inquisitive nature. Her portrayal consistently shows her supportive role and involvement alongside Vicky in key adventures.