They need to be known to be able to exist in our world. Ethnui was more powerful than Odin (discounting softer power like allies and being smarter). This suggests that being known isn't what gives them power. If it was, Odin would be more powerful than Ethniu. I'm pretty sure Odin is much more widely known than Ethnui. What do they need to be powerful in our world?
Jim said that Odin gave up (I think he said god status or Immortality or something like that) so he could have more influence in the mortal world. So I don't think she was more powerful than him, only he made a choice to remove some of that power. She said as much in the book.
