Later that season, Nielsen was promoted to third on the team and they won a silver medal at the 2005 European Youth Olympic Winter Festival.

Also that season, Nielsen skipped the Danish team to a bronze medal finish at the 2006 World Junior Curling Championships.

She and her team finished in fourth place after a close loss in the bronze medal game to Wang Bingyu.

Nielsen's rink played in their first Grand Slam event at the 2013 Curlers Corner Autumn Gold Curling Classic, where they won two games, but were eliminated before the playoffs.

Nielsen skipped the Danish women's team at the 2014 Winter Olympics, where she was also the flag bearer for Denmark in the opening ceremonies.