"What happened when you were kidnapped?"
Not letting her genuine emotions show on her face, Rebekah calmly closed her eyes.
"Haa," she heaved an almost silent inaudible sigh and began thinking.
What could she do in this situation now? She can't lie, no.
Her father could hear her heartbeat, and she wasn't confident enough in herself to be able to keep her calm while lying through her teeth about such a significant matter
She can tell them the truth. Yeah, after all, Sam did put her brother in the harm's way.
But she didn't entertain that thought much and discarded it.
Who was she kidding? She can't tell him the truth.
For two reasons. First, what would she respond if her father asked something like, "Why didn't you tell us sooner if you already knew Progenitor's identity?"
Second, she still needed Sam to kill her father. That's the only way she could achieve her dream life with her brother.