From The Grey House:
She gave a short, humorless laugh. “Other than the time your man took my blood as a warning?”
They stared at each other for a moment before Vincent answered. “Yes.”
“Three times that I know of.”
It was his turn to frown. He held out his hand to her. She took it and willingly sat in his lap when he pulled her closer. “Donald took your blood, yes?”
“Yes.” She wondered how much Vincent knew about her. That was a discussion for another day.
“Who else?” He guessed from the police reports that Donald took her blood. She never stated it explicitly, but then, no one could really tell the police about vampire attacks and be believed.