Free people dress size 4

Beautiful dress. Bottom is 100% silk. Top is 10% lyocell and 90% spandex (very stretchy). Tie ribbon at back of neck. Buttons up the front. Cotton slip underneath. Bought this new from Free People and never wore this dress but somehow on the back of the dress there is a small stain on one of the white petals, as pictured. Looks like dry cleaning would take care of this.