Poll

You should read assassins blade third, as per chronological order. The emotional effect will be more powerful than reading it first.
There is a reason why she wrote it third and I would trust the authors writing. Reading it first will not be have the same gut punching effect like it would third.

Also I strong recommend doing a tandem read between Tower and Empire books. It will feel like the most amazing movie.

The first time I read throne of glass I read assassin's blade first and I liked that throne of glass picked up right where it left off, and I think that it kind of gives you more of a glimpse as to what your getting into in the books.

But when I re-read the series I read assassins blade third and it does have more of an emotional effect. So I would still say read it first, but really just do whatever you’re feeling when you get them. Like do you want to see a little background and what your getting into, or do you want to have that huge emotional gut-punching moment.