Most annoying was the poor editing, blame it on the authors or the editor as you will. Not in the typos/grammar sense, but in the plot line. I'm a pretty head-down reader, and lots of inconsistencies and such can go right by me, but in Dragon's Kin, they jerked me from the story several times. Such as the early scene where Kindan, the protagonist, sees and explains how a watch-wher goes between. In the middle of the book, Kindan wonders if his young watch-wher could be taught to go between, "like a dragon", and the discussion continues to conclude that watch-whers couldn't be taught that, only dragons and fire-lizards. Then in the book's climax, Kindan asserts that watch-whers can go between as he saw his father's do it.
The other example now escapes me, but it was an info-dump that was repeated early on, leading me to say "but you just told us that!"
Oh, well, I still enjoyed the story, and will pass it on to see if my niece might like it.