She's 26 (as of 2013)
One way to distinguish Korean male names from female names is by looking at the last syllable of the name. Female names often end with the vowel "아" (a) or "애" (ae), while male names usually end with consonants or other vowels. Additionally, traditional Korean male names may have the syllable "석" (seok) or "준" (jun) in them.
Lee Jae Jin was born in 1979.
Lee Jin-a was born on 1985-03-10.
Min Jin Lee was born in 1968.
Lee Sung-Jin was born in 1985.
Lee Jin-il was born in 1973.
Lee Jin was born on March 21, 1980.
Lee Jin was born on March 21, 1980.
Lee Yoo-jin was born on January 8, 1977.
Lee Hee-Jin was born on 1980-02-21.
Lee Myung-jin was born on 1974-04-12.
Lee Hyun-jin was born on 1985-03-05.