Long flowy lavender gown

PLEASE READ !! I’m not too positive on the size being 18 so here are the measurements. There is no tag on the dress so that’s why I can’t be sure and it was altered but can be taken out. Waist 40 inches (it was taken in 3/4 in on both sides but can be taken out. Original waist would be 41.5 inches) Bust 43.5 inches ( does have built in cups ) Hollow to Hem 63 inches Sleeves are have a shear mesh and then lace on top.