Heron was fifth in the 200 - yard individual medley in 2 : 08.54 after going a best time 2 : 08.03 in prelims .
Heron is the youngest swimmer in the final .
Heron , the youngest swimmer in the final , was fifth in the 200 - yard individual medley in 2 : 08.54 after going a best time 2 : 08.03 in prelims .