So sweet for your little one!
0-2 months: EU 15, foot length 3.5-3.8 inches
2-5 months: EU 16, foot length 3.8-3.9 inches
5-7 months: EU 17, foot length 3.9-4.3 inches
7-9 months: EU 18, foot length 4.3-4.7 inches
9-11 months: EU 19, foot length 4.7 inches