However, later I reflected on a number of things that told against this.
Basically it was the explanation of Kevin's Dirt. Esmer said that Kastenessen and Esmer were channeling Her power to make this. Both of these characters have entirely obvious connections to Emereau Vrai. In fact we are told that Vrai used Her power to create the Dancers of the Sea. So the princess having the knowledge of Her true name is motivated after all.
Anyway... another scene that made a lot more sense on seventh thought
![Razz :P](./images/smilies/icon_razz.gif)
In fact, that's the deeper twist: the prison for the Creator would have been the rebuilt world had Jeremiah not defeated the Raver. The Despiser was going to use Roger and Jeremiah, if possible, to create a new reality, one in which the Creator was trapped as the Despiser had been. And that world would have indeed been the Gallows-fell spoken of by the Clave.
EDIT: Also, Her true name is a song. That's what all the musical description stuff is about, when the Demondim-spawn basically sing Her true name to Her. Only there are no clear lyrics, only instrumentation, as it were.