Erdem Floral Dress Approx. comparable to US size 6

I purchased this as a preowned item. It does not have a size listed. See measurements for sizing In my opinion this would fit no bigger than a size 6 I am size 8 and am able to fit into it and wore it once but it is too tight for me. So although I love this dress I would rather sell it than risk damaging it This is a High end brand