Rubuta ci gaba don wannan sakin layi - Gasar ta farko ta kasa da kasa ita ce Gasar Zakarun Duniya ta 2004 ta IAAF, inda ta gama ta huɗu a cikin zafin ta. Kowalska ya lashe lambar zinare a gasar zakarun Turai ta 'yan kasa da shekaru 23 a shekarar 2005. A shekara ta 2006, ta lashe tagulla a gasar cin kofin Turai
kuma a gasar zakarun Turai ta 2006 ta yi rikodin mafi kyawun lokaci na 9:42.50 a cikin cancantar kafin ta ci gaba da kammala na tara a wasan karshe. Ta wakilci Turai a cikin mita 5000 a gasar cin kofin duniya ta IAAF ta 2006 a Athens amma ta gama a matsayi na karshe. Ta yi tsere a Gasar Zakarun Turai ta 2006 a tseren 'yan kasa da shekaru 23 kuma duk da cewa ta gama ta tara, ta jagoranci Poland zuwa lambar azurfa ta tawagar.