Milla Jovovich only 16?

She was born in 1975, which makes her only 16 years old when they made this movie, in 1991. I couldnt belive that. I was only about 8 when this movie came out, and it has remained one of my favorites but it was only until now that I found out what year she was born. She looks and acts as if she is at least 25 in the movie. Did anyone else find it shocking she is so young in that movie?