I am sure your little one will love this cardigan and will feel very comfy wearing it. It is easy and quickly to make it, as you have to work with worsted weight yarn.
I also wrote pattern for matching Sorrento Slippers

Sizes
3-6, 6-9 and 9-12 months
Finished Chest: 50 56, 60 cm or 19 ½ 22, 23 ½ inches
Finished Length: 24 28, 30 cm, 9 ½, 11, 11 ½