Fleming skipped Scotland at two straight World Junior Curling Championships. At the 2012 World Junior Curling Championships, she led her rink of Lauren Gray, Alice Spence and Abi Brown to a 7-2 round robin record. In the playoffs, they knocked off the Czechs (skip: Zuzana Hajkova) twice to claim the gold medal. At the 2013 World Junior Curling Championships, Fleming led her rink of Gray, Jennifer Dodds and Brown to an 8-1 round robin record. In the playoffs, they beat the Japanese team (skip: Sayaka Yoshimura) in the 1 vs. 2 game, but lost in the final to Team Russia, skipped by Alina Kovaleva.