You will need

Sweater and Jacket
(with long sleeves)
3 - 6 months (16in Chest) 2 Balls
6 - 9 months (18in Chest) 2 Balls
9 - 12 months (20in Chest) 3 Balls
12 - 18 months (22in Chest) 3 Balls
18 - 24 months (24in Chest) 4 Balls

Bolero
(with short sleeves)
3 - 6 months (16in Chest) 1 Balls
6 - 9 months (18in Chest) 2 Balls
9 - 12 months (20in Chest) 2 Balls
12 - 18 months (22in Chest) 3 Balls
18 - 24 months (24in Chest) 3 Balls

Hat
1 Ball for all sizes

7mm and 8mm Needles
4 (4 : 4 : 5 : 5) Buttons for Jacket
1 Button for Sweater
1 Button for Bolero