Kammala jumla mai zuwa: Ta fara fitowa ta farko a gasar tseren matasa a gasar tseren tsere ta duniya ta 2003 IAAF, inda ta gama a matsayi na biyar kuma ta lashe lambar azurfa ta matasa tare da Peninah Jepchumba. Ta yi gasa a tarurruka a Spain da Portugal a shekara ta 2004, tana gudu a mita 1500, mita 3000 da kuma wasu tsere na 10K. A shekara mai zuwa ta rasa wani wuri a tawagar 'yan kasa a tseren ƙasa amma ta kafa mafi kyawun mita 3000 na minti 8:53.46 a Meeting Gaz de France a Paris. Bayan da ta ɗauki matsayi na biyu a Gasar Wasannin Wasanni ta Kenya, Chebet ta sami babban matsayi na farko a Gasar Zakarun Afirka ta 2006, inda ta kasance ta lashe lambar tagulla a bayan 'yan uwanta na Kenya Edith Masai da Isabella Ochichi. A 2007, ba ta gama a zafin Mombasa a gasar cin kofin duniya ba.
2007 IAAF Gasar Cin Kofin Duniya, amma ta lashe mita 10,000. Ta gama na tara a tseren mita 10,000 a Gasar Cin Kofin Duniya ta 2007. A cikin tafiyarta ta ƙarshe ta shekara ta taimaka wa Kenya zuwa matsayi na biyu a cikin Chiba Ekiden Relay, bayan da ta gudu da nisan kilomita 5.