It's been awhile since I reviewed a book, sorry. At least this review is chronological. Enna Burning is the next book after Goose Girl. I liked it just as much.
Keeping in mind that this is a fairy tale and written for young adults, I think it accomplishes its goals. I like the characters. Even more than the first book, the protagonist is flawed. Enna is a good person, and her motivations are also good, but she has to combat urges and desires that lead her astray. I think that's an important and realistic theme.
Isi is a supportive character in this book, while Enna takes over as the story's main focus. I was drawn in and wanted to keep reading to see what choices she would make and how they would affect those around her.
There's a cool quote, "what she had seen when she loved him had faded and in its place...." I think it sums up exactly what you want to be able to do when you have moved on to a new interest. Being able to see someone more objectively, and not be taken in by them.
I recommend this book. But read Goose Girl first.
And one warning. This is more violent than the first. After all there is a war, and the main characters are soldiers in the war.