Priest Kanis:
I was able to determine the Shamaness' location by using a relic of Eva that contains the power of the Water Dragon.
...
Take this Echo Crystal for now.
When I confirmed her location through the relic, I was also able to ascertain a little about her condition.
It seems that her mind has been sealed in order to block her from communicating with the Water Dragon.
When you find her, you may need this Echo Crystal, which contains the voice of her mother, also a famous priestess.
Take the Echo Crystal from Kanis.