No, she knows about Exador the archdemon.
What he’s saying is that
1) Exador was a demon, we assume Ramses is a demon, Bess maybe a demon but we don’t have proof that she’s also a goddess slumming as a demon. That would be very weird for these guys, a god pretending to be an arch-demon????
2) He’s saying, perhaps wishfully that they don’t know that the former Arch-Vicar General of the Rod was the same arch-demon Exador, they just happen to have the same name. Again, comes down to the fact that they can’t conceive that an arch-demon could fool the church and the avatars and rise to the level of arch-vicar general, that’s like saying the highest ranking Cardinal in the Catholic Church is a demon lord. Of course, today many people suspect aht, but…that’s protestant cynicism