You will need a size US 7 (4.5 mm) circular needle for the neck finishing.

Finished measurements:
Bust circumference: 41.5( 45.75, 49, 53, 57.25, 61.5, 64.5, 68.75, 73.75)“ 105.5( 116, 124, 134.5, 145.5, 156, 164, 174.5, 187.5) cm
Finished length: 22.75( 23.5, 24.5, 25.25, 26, 26.75, 27.25, 28, 28.25)” 58(60, 62, 64, 66, 68, 69, 71, 72) cm
Sleeve to underarm: 17.25(17.75, 17.75, 18, 18, 18, 18, 18, 18)“ 44(45, 45, 46, 46, 46, 46, 46, 46) cm

Yarn used
Rowan Kid Classic
Shade 898 Champagne - 7(7, 8, 8, 9, 9, 10, 10, 11) balls

Yes, the pattern is really named Chlo - not a typo.