[3] Internationally, she began her career as a junior athlete by winning the 100 metres title at the 1997 European Youth Olympic Festival.

[5] She ran at the next edition of the world competition in 2000 and, after coming sixth in the 100 m hurdles, she claimed her first medal with the Swedish women's 4×100 m relay team.

Alongside Linda Fernström, Emma Rienas and her twin Susanna, she took the bronze medal with a national junior record of 44.78 seconds.

[6] She moved up an age level to take part in the 2001 European Athletics U23 Championships and she won the silver medal in the 100 m hurdles, finishing behind her sister.

She was chosen to represent Sweden in the hurdles at the 2005 World Championships in Athletics and she ran a career best of 12.85 seconds to make her first major outdoor final.

She came sixth in the hurdles final and later ran a Swedish record of 43.67 seconds in the 4×100 m relay, in a team comprising the Kallur twins, Emma Rienas and Carolina Klüft.

[11] Kallur's injuries continued to persist and when a separate foot problem emerged in 2011 she decided to call an end to her athletics career at the age of thirty.