You will also need a circular needle size US 3 (3.25 mm) 16” (40 cm)
You will also need stitch holders.

Finished measurements:
Back width: 19(21, 22.75)“ 48(53, 48) cm
Finished length: 24.75(26, 27)” 63(66, 69) cm
Sleeve length including ruffles: 17.75” (45 cm) for all sizes

Yarn used:
Rowan Baby Merino Silk DK
15(16 ,17) balls # 670 Snowdrop