Mabergs played lead on the Swedish junior women's team at the 2011 and 2012 World Junior Curling Championships, on teams skipped by Jonna McManus and Sara McManus respectively. At both events, Sweden placed fourth. Mabergs played third on the Swedish team, skipped by Sara McManus, at the 2013 World Junior Curling Championships. That team would place fifth. Mabergs played lead for the University of Gävle team representing Sweden (and again, skipped by Sara McManus) at the 2015 Winter Universiade. There, the team finished fourth.