shes young, didnt she used to live in the state and move to china ?
She was born in Hubei, China with a birth name of "An Feng". Her parents divorced when she was 10. When she was 11 years old, Liu and her mother moved to New York City, where she attended Louis Pasteur Middle School. She returned back to China to pursue an acting career and adopted the stage name "Liu Yifei". Liu was accepted into the Performance Institute of Beijing Film Academy at the age of 15 and graduated in 2006.
Immediately after her admittance into the Beijing Film Academy, Liu received offers to star in various television series. Her debut appearance on television was in The Story of a Noble Family. Shortly after, she was chosen to play Wang Yuyan in Demi-Gods and Semi-Devils. Initially, Liu Tao was selected for the role of Wang Yuyan but it went to Liu Yifei eventually and Liu Tao was cast as A'zhu instead.
In 2005, Liu starred as Zhao Ling'er in Chinese Paladin. The following year, she starred in The Return of the Condor Heroes. After intense speculation on who would play Xiaolongnu, the role was finally offered to her. She was backed by Cha, who felt that she had all the necessary qualities to portray the young and innocent female protagonist. Although the television series she acted in were well-received, most of the films she starred in did poorly in terms of box office earnings.
I personally think that most Chinese actress/actor, majority of them did starts acting in show/film since they were very young. So when they became known or famous, they would still be at a young age. At the moment, she is now she is 26 years old.
But then again, there are now many acting stars in America who starts acting when they were just a baby.