She sighed. "I kinda figured."

I hate this part of the conversation. It's always so much easier after, though. Assuming you actually get to the 'after' part.

Diana held up her hands, palms out. "Look, don't freak out, okay? I'm a nice person and I... I don't want you to get the wrong idea about me. Eliot knows all about this and he's cool with it, I swear. You can ask him. But...uh...yeah. So. I'm kinda a...vampire."