You will need 4(5, 5, 5, 5) small buttons

Finished measurements:
Back: 9.25(10.5 ,11, 11.75, 12.5)“ 23.5(26.5, 28, 30, 32) cm
Length: 8.25(9.75, 11.5, 13, 14.5)” 21(25, 29, 33, 36) cm
Sleeve length: 5(6.75, 7.75, 9, 10.25)“ 13(16, 20, 23, 26) cm

Yarn used:
Rowan Baby Merino Silk DK
Pebble 690 3(3, 3, 4, 4) balls