Emily Infield.
She seems humble, grateful, and hard-working, and has been challenged by injuries. My kind of athlete. Pretty much the opposite of the typical 100m proud peacock athlete. With her injuries, she is again the underdog, which makes me want her to succeed even more.
I think you can argue that her World Championship bronze was not luck. She ran both hard and smart, and was obviously in amazing shape. She earned that bronze.