You will need one button. Rowan used # 1470/12 from Bedecked in the UK.

Finished measurements:
Bust circumference: 36.5(40.5(44.5, 48.5, 52.5) ‘ 93(103, 113, 123, 133) cm
Finished length: 21.5(22.5, 23, 24, 25)“ 55(57, 59, 61, 63) cm
Sleeve from wrist (above cuff) to armhole: 14.5914.5, 15, 15, 15)” 37(37, 38,38, 38) cm

Yarn used:
Rowan Valley Tweed
Hardaw 108 - 7(7, 8, 8, 9) hanks