There is little background information known about Karen. She is very protective of her employer, Lisa Wong, and she is a well-accomplished assassin.
She ambushed Beatrix at her hotel room shortly after Beatrix discovered that she was pregnant. Karen fought with a shotgun while Beatrix used a pistol. Beatrix also threw a knife at Karen which she blocked with the butt of her shotgun. The fight then stopped while Beatrix explained the fear of her pregnancy to Karen. Karen agreed to go back home if Beatrix would do the same. Before leaving, Karen congratulated her on her pregnancy.
Regardless of her being an assassin, Karen is shown to have a conscience. She chooses not to complete her assignment because she discovers Beatrix is pregnant.
- Close-Range Weaponry: Karen is highly skilled with a shotgun. She even claims she's a "f---ing surgeon" with it.
- Deception: Karen is able to disguise herself to hide her true identity. She briefly convinces Beatrix that she is actually a hotel employee. She uses this disguise to get the upper hand in the fight that ensues.
- Originally Karen was intended to be the sister of Lisa Wong, as evidenced by the original draft of the script for the film.