Brand New Floral B&W Dress AU S-M check measurements

Brand new never been worn very pretty dress. Was excited to wear this but doesn't fit me. Beautiful soft fabric and such a cute print! Back is elasticated see photos. Cute frill. Measurements taken with garment lying flat. Arm pit to armpit 40 cm without stretching the back Waist approx 36 cm Length 84 cm app taken from shoulder (including the strap) Label say US L but I would think this might be a AU S to M