Pretty White and Black Strapless Holiday Dress

Pretty strapless dress with white top, black lace bodice, and black net skirt. Has a pretty sash with a jewel on the front and ties into a bow in the back. Perfect condition, Only worn once! The dress has a tag but does not list the size on the tag, so I'm not sure of the exact size. I used to fit into it when I was around a size 4-6. I think the best size reference would be a medium.