When I first saw the movie, I didn't have a clue Trudy died. Trudy was in her ship, and Quaritch spotted her and realized she was a traitor. He ordered the pilot of his gunship to kill her. They continued to fire, and she hung in there for quite a while, despite her ship catching on fire and getting her window blasted. Finally she turned on Quaritch and yelled, "You ain't the only one with a gun, bitch!" She then contacted Jake, and even though he couldnt hear her, she told him she was hit and she had no choice but to take her final stand. She shot directly at Quaritch, but her ship exploded too soon. She most likely will not return in Avatar 2.