Tenenbaum is having trouble with her expression. She's already dealing with being tired and worried and guilty and god knows what else; she didn't really need the stress of this bad a secret coming out. And okay, maybe she deserves it, but that doesn't mean Jack does.

Sinclair's private little laugh kind of makes her hate him.

"And the child, he... he knows you have learned it all?"

She's not even sure how exactly how much Jack knows, beyond a certain point. She'd ask, or tell him if he wants to know, but... they haven't talked very much, outside of what to do and where it must be done. When he woke up in her safehouse, he only said a little, and left quickly. And when she saw the faces of her girls she didn't try to keep him there.