Career
She made her Olympics debut at the 2012 games where she was taking part in the 100 and 200 m backstroke and the 4×100 m relays in freestyle and medley.
She made her Olympics debut at the 2012 games where she was taking part in the 100 and 200 m backstroke and the 4×100 m relays in freestyle and medley.
Nielsen won her first international senior medals at the 2011 European Short Course Swimming Championships, where she won four medals and was named newcomer of the championship. She is the daughter of Benny Nielsen, who won silver in the 200 m butterfly at the 1988 Summer Olympics and Lone Jensen, who participated in the 1978 World Aquatics Championships.