If she discovered that she was the first person William Wood had ever murdered, she wouldn't have been surprised in the slightest. In fact, she would've been more shocked to learn that he'd killed before. There was a certain amount of confidence that a person who'd witnessed the light fade out of a person's eyes at their hands had that he simply didn't possess. He was hesitant at first, unsure in his movements. For a man who was brash and full of threats, to actually be faced with the task of committing the murder he'd been dreaming about, he was struggling. He was the sort of would-be murderer that she would've been easily able to persuade not to follow through with his plan if she had the use of her voice. It was a good thing for him that he had the presence of mind to silence her. While he likely did it to keep her screams from being heard by the staff of the hospital just outside in the corridor, it served an additional purpose. She could've easily talked him into walking away.