In June 2007 she finished fifth in the 400 metres race at the Kenyan Championships with a time of 55.82 seconds. She kept improving throughout the season, winning the 400 metres gold medal at the African Junior Championships with a finish of 54.93 s and setting a Kenyan national junior record in the 200 m with 24.68 s. Jelimo was pleased with her accomplishments but her new coach Zaid Kipkemboi Aziz suggested that she change to 800 m, stating that she would perform best over the longer distance. She began working for the Kenyan police force and was training with fellow Kenyan runner Janeth Jepkosgei.