Yu Zidi of China is only 12 years old and will race at the world swimming championships later this month in Singapore. That's amazing. But her age is only part of the picture.

Yu Zidi of China is only 12 years old and will race at the world swimming championships later this month in Singapore. That’s amazing. But her age is only part of the picture. In this photo ta ...

Yu Zidi of China is only 12 years old and will race at the world swimming championships later this month in Singapore.

Yu Zidi of China is only 12 years old and has qualified for the world swimming championships in Singapore. Her performances have stunned the swimming world. Yu’s times in the 200- and 400-meter ...

Yu Zidi of China is only 12 years old and has qualified for the world swimming championships in Singapore. Her performances have stunned the swimming world. Yu’s times in the 200- and 400-meter ...