Rue Sophie Eli midi dress - off white - medium - DISCOLORATION

Fair used condition. Faint stain on back (shown in last picture). Tried to spot treat and hand wash but could probably use another round. The top of the dress is also more of a beige/off-white than the bottom which is bright white. Marked size medium but fits more like a small - see measurements below. There’s a little give/stretch but not much, maybe an inch or so. Bust 16” Waist 13” Hip - open (around 30” across” Length 48”