Billious knows that it does not matter how bad the thing is, the hiding of it and the stalling is what hurts you, not the crimes themselves.
I think she says so because she doesn’t know just how much she “they” have on her.
She can’t dump too many documents because if she does some of them can be used to indict her—especially if “they” hadn’t known about it yet.
She’s always tried to play stupid when confronted. e.g, “Like with a cloth?”
She doesn’t know how much the FBI knows. She wants them to make more moves before she tries her next ploy.