"She's a very, very young elf. She's only 600 years old, unlike Legolas who's like, 1,900 years old and Thranduil who's about 3,000 years old. She doesn't have quite the wisdom and pose that those two boys do; she's a little more... gritty. A little more spontaneous, passionate perhaps."
The actress also spoke about the balance between her character's grace and her ruthless nature.
"To play this character I need to have a certain amount of grace]. But I'm also supposed to be an absolutely ruthless, deadly killer."
The Hobbit: The Desolation of Smaug was released December 13th, 2013 and stars Ian McKellen, Martin Freeman, Richard Armitage, Ken Stott, Graham McTavish, William Kircher, James Nesbitt, Stephen Hunter. The film is directed by Peter Jackson.