You will need one button - Rowan used #BN1368 from Bedecked in the UK.

Finished measurements:
Bust circumference: 43.75(47, 51.5, 55.75, 58.75)“ 111(119.5, 130.5, 141.5, 149.5) cm
Finished length: 27.25(28, 28.75, 29.5, 30.25)” 69(71, 73, 75, 77) cm
Sleeve to underarm: 17.25(17.25, 17.25, 17.75, 17.75)“ 44(44, 45, 45, 45) cm

Yarn used:
Rowan Island Blend Fine
Shade 104 Parakeet - 14(15, 17, 18, 20) hanks