I loved this book, so please take things just as a minor criticism.
Why using the name "Espira"? That is the Spanish word for Spire, so if the book is translated to Spanish it will be confusing. So many names...was "Espira" really needed? I know you cannot keep track of all the languages for not using anything weird in the names, but Spanish is quite a popular language in USA so the problem is easy to spot.
Unless, of course, there is a reason, like Folly's dream about a Spire falling actually meant Espira falling.
(oh, and I have to say it and this is a place as good as any other. I don't like the fact that Gwen is Gwendolyn Margaret and MArgaret LeFay is Margaret Gwendolyn. Hubby thinks it's a good wink from Spires to Dresden Files, but I don't like it at all)