Her international debut for Great Britain followed at the 2011 World Youth Championships in Athletics, where she placed eleventh in the steeplechase final. Markovc competed in her first major cross country running event at the 2013 IAAF World Cross Country Championships, placing 21st in the junior race. She was also a steeplechase finalist at the 2013 European Athletics Junior Championships and 2014 World Junior Championships in Athletics. After the latter event she did not compete for 18 months.