The bodice is cut on bias and that makes it flexible, I used a thin cotton and had to ad an elastic in the waist to keep it from growing. My fabric was not very sturdy so I lined the bodice. Without the lining I think that that pattern rating “easy” is appropriate. That fact that it is cut on bias makes it a bit more forgiving to any problems with the fit.
The skirt is really full and cut lengthwise, I made mine smaller and cut it across the fabric. I used 2,7 m instead of the 3,6 meters listed on the envelope.