From The Grey House:
She opened her eyes and gave him a frank look. “There are many things I have allowed that hurt me in order to stop monsters from destroying the people I love.”
He gave her a smirk. “Who were you protecting this time? Bethany?”
The color drained from Natalia’s face. As far as she remembered, she never once mentioned her best friend to Zechariah or any Slayer. “Why did you bring her up?”