In 2012, she began competing a higher profile races, but did not place as highly, though she was second at the Zwolle Half Marathon. She missed the 2013 season but returned in mid-2014 with a string of victories, including the Alsterlauf, Bredase Singelloop (in a best of 68:40 minutes) and the Paris 20K. She continued this into 2015 by winning the Adana Half Marathon, San Blas Half Marathon and the Lisbon Half Marathon, winning the latter in a new best of 68:22 minutes.[3] After a win at the České Budějovice Half Marathon,[5] she gained Bahraini citizenship and began competing for that country.[3]
Chelimo started 2016 with two personal bests. She ran 68:08 minutes for eighth at the RAK Half Marathon, then won her debut race at the Seoul International Marathon, crossing the line in 2:24:14 hours.[6] In her Olympic debut at the 2016 Rio Games she had an eighth-place finish in 2:27:36 hours, while her teammate Eunice Kirwa took the silver.