6 9 12 18 24 36 Months Baby Girls Clothing Sets Cute Style Knit Vest + Shirt + Plaid Pleated Skirt 3pcs Baby Suits Kids Clothes

it is more correct to compare with the height:
(Unit：CM)
6-9M：Vest length=30 Shirt length=31 Bust=56 Skirt length=23：fits for: 66-73cm height / 6-9 Months

9-12M：Vest length=32 Shirt length=33 Bust=58 Skirt length=25：fits for: 73-80cm height / 9-12 Months

12-18M：Vest length=34 Shirt length=35 Bust=60 Skirt length=26：fits for: 80-85cm height / 12-18 Months

18-24M：Vest length=36 Shirt length=37 Bust=62 Skirt length=28：fits for: 80-90cm height / 18-24 Months

2-3Y：：Vest length=38 Shirt length=39 Bust=64 Skirt length=29：fits for: 90-100cm height / 2-3 Years Old
Note:
1.There is 2-3% difference according to manual measurement.(1 inch = 2.54 cm)
2.All measurement in cm, please note 1cm=0.3937ch, 1 inch=2.540cm
3.Please check the figures carefully and order the right size, don't completely depend on the " age advice". It's just for reference.