Youngji used to be a CCM trainee and she was really good at dancing... She has danced to song like Sherlock(shinee) Bang(after school) Bad Girl Good Girl(Miss A) And many 更多 你 will see proof in this links
搜索 this for 更多 covers 由 her : link
and also the boys cover : link
In the 显示 where they showed off charns and such she showed that she could dance to the songs (some of them)
In Weekly Idol there she danced to sherlock and warrior.
你 could also 搜索 on google: Youngji dance.