McManus was the alternate for the Swedish team at the 2009 and 2010 World Junior Curling Championships. The team, which was skipped by Anna Hasselborg finished in sixth place in 2009 and won the gold medal in 2010. While McManus was listed as an alternate, the team acted as a five-player team, with McManus throwing lead rocks in most of the team's games. The team was taken over by McManus' sister Jonna as skip for the 2011 World Junior Curling Championships where the team placed fourth, with Sara throwing third stones.