Kristen Stewart keeps to herself as she arrives at LAX airport in Los Angeles for an early morning flight on Sunday (March 18).

Earlier over the weekend, the 21-year-old actress and Charlize Theron attended WonderCon 2012 to present and talk about their upcoming film, Snow White and the Huntsman.

Chatting with Collider, director Rupert Sanders opened up about casting Kristen in the lead role.

“I think what I realized is that she’s such a good actor that everyone thinks she’s Bella Swan,” he shared. “They believe that that’s her. Obviously, an actor is playing a role. She is nothing like Bella. And, I got on really well with Kristen. It was great. As I was writing stuff, she was there. We had a lot of conversations, seeing through her eyes. We really hard on developing that character together.”

He added, “I was just amazed at her talent, really. She’s incredibly good at her craft. She’s incredibly instinctive. She’s incredibly intuitive. She will overcome fear, like no one I’ve met, when it comes to it.”