You will need

0-6 mths - 2 Balls
6-12 mths - 2 Balls
1-2 years - 3 Balls
2-3 years - 3 Balls
4-5 years - 4 Balls
6-7 years - 4 Balls

3.25mm and 4mm Needles
Stitch Holders
1 Button