Yeah, I'd figured out the "big reveal" before the book had even postulated that it was possible. I choose to believe this is intentional, because Seanan can be sneaky when she wants to, so I don't think she wanted to. I will admit it was a bit frustrating to me, though, to constantly go "WELL DUH BECAUSE X!"

I did see a post on...goodreads, I think? where someone was like "How could Symbogenesis not have known?" and it threw me, because to me, OBVIOUSLY they knew. Why else would they be so interested in her? It wasn't simply because her worm "saved" her. They knew full well what was going on, and wanted to study it. And they didn't want her to know.