I have already gave you one reference where she is called insane in clinical sence and here is the second, from the "Narrator":There's no reference of her being actually insane or being normal prior to her burning.
Come on, this girl is not wearing any shoes and does not remember her own name, despite being around 40yo when Hulrun tried to burn her during the Third Crusade. She may be very, very special - but she is not sane with any stretch of definition.The mob loves a wretch, a feeble-minded, hysterical, starry-eyed preacher — when one of these unfortunates stands on a corner and begins their sermon, a crowd will immediately gather.
1. Staunton is not the word of god and furthermore your enemy.
2. The second description is very obviously taking the point of view of the mob's superficial perception of Ember and is in no way indicative of her actual character.
She definitely isn't "normal" but not crazy. Her worldview is coherent and her preaching actually works.