Dahlgren has represented Argentina at the 2004 and 2008 Summer Olympics,[2] as well as having competed at the World Championships in Athletics on three occasions.

[3] Dahlgren's first major tournament was the 2000 World Junior Championships in Athletics, but she did not make the final, finishing 11th in the qualifying stages.

However, she did not fare as well at the 2004 Summer Olympics, managing a throw of only 59.52 m. In 2005, she improved her record to 67.07 m and bettered her previous performance at the NCAA Championships with a second-place finish.

[9] She started 2007 by winning the NCAA championships with a mark of 70.72 m (her final amateur title) and throwing a new South American record of 72.01 m soon afterwards in Greensboro, North Carolina.

[4] She scored her first major championship medal at the 2007 Pan American Games, taking the bronze with a throw of 68.37 m behind Cubans Yipsi Moreno and Arasay Thondike.

[14] Despite this, she was also the best South American performer in the hammer at the 2009 World Championships in Athletics, where her throw of 68.90 m was good enough for 17th, but not enough to make the final round.

[15] Dahlgren frequently moved with her family in her youth, which meant that she spent much time living in the United States.