That was the driving force, wasn't it? She was learning more and more about what made immortals tick, what made them who they were. She let the silence sit for a while, until the GPS lead them into the parking garage and informed them that "you have reached your final destination. Welcome home."
She turned off the engine and unbuckled her seat belt, but didn't get out yet. She wasn't quite ready to leave the small amount of freedom she'd felt.