She could be more vague, but there was only so much she could say. He does ask two questions that she can answer, though, so she'll give him that much.

"He wants this planet to be saved, so he can repeat this solution again and again." She offers, before clarifying: "I know we haven't found the solution yet. It's not this."

And then there's that second question and she pauses for a moment to decide how best to phrase it...

"Because he will kill you otherwise. If you can't lie, I can actually threaten you."