You will need 5 buttons. Rowan used #BN1562 from Bedecked.

Finished measurements:
Circumference at bust: 34.5(38, 42.5, 46, 50.5)“ 88(97, 108, 117, 128) cm
Finished length: 23(23.5, 24.5, 25, 26)” 58(60, 62, 64, 66) cm
Sleeve length to underarm: 17.5(17.5, 18, 18, 18)“ 45(45, 46, 46,46) cm

Yarn Used:
Rowan Cashmere Tweed
Shade 013 Yorkshire 11(13, 14, 15, 16) balls