Cherono made her first international appearance at the 2007 IAAF World Cross Country Championships in Mombasa and she finished 23rd in the junior race. She reached her first international podium at the 2007 World Youth Championships as she ran a championship record time of 8:53.94 to win the gold medal in the 3000 metres. She had a successful cross county season at the end of the year, taking 6 km junior race victories in three of the Athletics Kenya meetings. She had back-to-back wins in the junior race at the Tuskys Wareng Cross Country in 2007 and 2008.