Here's what you need to know about Kate:
* She's a member of the Denali coven. This coven is known for being peaceful and vegetarian (they only drink animal blood).
* She's the sister of Eleazar. Together, they are the closest to Bella Swan in the coven.
* She is a strong and compassionate vampire. She is understanding and accepting of Bella's human nature, even though she is initially skeptical of Bella's relationship with Edward.
* She plays a key role in the events of "Breaking Dawn." She helps to protect Bella and Renesmee during the Volturi's visit, and she is a strong voice of reason in the face of the Volturi's judgment.
While she doesn't have a huge role in the story, Kate's presence adds depth to the world of vampires and provides a valuable perspective on Bella's situation.