If something in your head feels wrong, or at least not quite right, that's likely her. Your mind knows, even if you can't pinpoint it consciously.
[Faith] After you're done punching things, come to the apartment. I'll teach you some of my best tricks. It won't keep anyone completely at bay from poking around in your mind, but it'll help bury the worst memories far enough that you can protect them until we get her back to normal.