VENUS Black & Gold Boho Beaded Embroidered Maxi Dress Size 20

EUC from a smoke free home. Measures 22 inches from pit to pit lying flat. Waist measures 17 inches across front unstretched. Measures about 58 inches long. This was my sister’s dress so I have not tried it on but it seems smaller than a 20 to me, maybe more like a 16/18.