Certain things were starting to fall into place, based on the timeline she'd been given from the newest version of Cas. She remembered him telling her about how he'd nearly died when the leviathans had taken him over and been essentially reborn with very few powers and little memory of what had happened. He hadn't mentioned Meg being the one to find him, but maybe that was where their universes differed. Or maybe she had still found him, but things hadn't worked out with them in quite the same way-- maybe even gone badly-- which would explain why he wouldn't mention it. But he'd seemed to know her, all the same. And while she wasn't sure about where Meg factored into what the new Cas had told her, the hesitance of the first Cas (she was seriously going to have to come up with better ways to distinguish them from each other in her mind, she thought wryly) to explain what had happened to him now made quite a bit more sense. Assuming, of course, that things had gone down relatively similarly between worlds, which may or may not have been an assumption worth making.
Regardless, she really would have liked it if Meg's Cas had simply been fully honest with her. He'd acknowledged the vague fact that he'd made mistakes and his state of health was his own doing, but that was far less information than had been offered by the newer, more human, version of him. It was inconsequential, really-- the information itself didn't particularly matter-- so long as it didn't indicate a lack of trust between them.
Her concern about trust approximately doubled with Meg's non-answer to her question about what she was. "So you're a demon," she said evenly. It wasn't quite a question, but there was room for Meg to dispute it. She was fairly certain she was right, though. Otherwise, why would she have brought up demons at all, or been so quick to point out that she wanted to stab most of them in the face, when Sam hadn't even mentioned demons?
She really wasn't quite sure what to do with that news. She knew what Deanna or her mother would have done-- you find out she's a demon, you go for the holy water, you don't chat-- and she knew what her own instincts were telling her, which were essentially along the same lines. But she stayed where she was, because...well, for much the same reasons why she hadn't gone after Anna when she'd found out who she was. There was a bigger picture here. They could all cease to exist practically at any moment and anyone who was even vaguely useful, whom she could trust at least to wait to try to murder her until the realities had stopped collapsing, was an ally she was willing to consider. Or at the very least, she wouldn't try to murder them until the realities had stopped collapsing, either.
But Meg was someone that Cas had trusted before he'd gotten here. Even Sam had to admit that it sounded unusually helpful for a demon to nurse an angel back to health rather than take advantage of their mojo-less state to kill or torture them for information. But then again, a demon had gotten Sam all cleaned up and taught her to use her powers for truly awful purposes, and she was sure that a demon could think of a good reason to do the same with Cas. After all, according to Cas himself, Crowley had certainly found him useful.
Meg wasn't Crowley, nor was she Ruby. She wasn't sure if Meg was a demon she'd met before, or not-- she knew a Mel, but the girl in front of her bore almost no resemblance to him, and not only in terms of the meat suit. Mel had been all about tormenting her and her family, and pledging his loyalty to Azazel and Lucifer. Sam couldn't really imagine any version of him ending up on their side after all of that, much less being trusted. But then again, maybe Meg was simply a drastically different version of him, but a version nonetheless.
"Where do... Dean and I factor into that?" She asked after a moment. She meant, how had they dealt with Cas being that badly off, and then shacking up with a demon, and...well, all of it. "Is it just you and Cas doing one thing and us doing something else, or do you work with us, still?"