Evangeline Lilly talks about her character
In the latest issue of Total Film, Evangeline Lilly told us that Tauriel is an "absolutely ruthless, deadly killer," quite different from any other character that has been in The Lord of the Rings or The Hobbit, aside from one or two of the meaner orcs. She is a new addition by Peter Jackson, so many fans are skeptical about this "spontaneous, passionate" elf. It will be interesting to see how she plays out in The Hobbit: The Desolation of Smaug.
Source: Total Film