"One of the tricky things is, vampires aren't supposed to age, so I'm not sure how much longer I will be able to do that," Greene, 25, said with a laugh. "Alice is such of an awesome character to play, so I wouldn't have a problem with doing more."

Greene said her biggest hesitation, though, is recapturing the magic of "The Twilight Saga" as it stands.

"I think we've ended things now on such of a positive high note that I would hate to extend things further and not have the same passion for it," Greene said. "That's what's been special for me, having this overwhelming excitement and joy that you get when you see how excited people get for what we're creating. I wouldn't want to lose that."