Despite my love for happy endings (and this is Cinderella, after all!), I am just not a big fan of how things turned out since book 5. The quest made little sense and even though the characters asked relevant questions, the most common answer we got was "Life is not fair", yet it does not really explain the mechanics of how things work.
The story ties everything with a pretty bow, but I honestly expected a bit more on the evil stepmother side. A little more backstory, a little more development, a little more something! We were told Salvia loved her father and despite everything that went down, it makes no sense to abuse her biological daughter as well this much. Which brings me to the next point of Sienna just disappearing without ever making an appearance in front of Elle, even when things were finally alright.
Then you have the king and the patched up solution they found to mitigate his hate (ignoring somehow all the atrocities that he has commited) and of course, my favorite character, the Godmother, who more or less kept beating the same drum and could get away with situations that made no sense for her without feeling everything was amiss.
All in all, a very enjoyable series which I think went a bit too far in its own universe and the explanations were either lacking or not existing, but I would definitely read it again if I could.