Choosha qualified for the 2012 Summer Olympics in London via a wildcard after long-distance runner Tonny Wamulwa was injured in a road traffic accident three weeks before the games started. She took part in the women's 100 meters in the preliminary round on 3 August and was drawn in heat one, finishing fourth out of eight athletes, with a time of 12:29 seconds. As of 2016, the time is her personal best. She ranked ahead of Afa Ismail from the Maldivies (12.52 seconds) and Jordan's Rima Taha (12.66 seconds) in a heat led by Feta Ahamada of the Comoros (11.81 seconds). Overall, she finished 57th out of 78 competitors, and did not advance into the first round because her fastest time was 0.05 seconds slower than the slowest athlete who progressed.