I bought 8 models and they are all beautiful. This is 100% cotton. Regarding sizes: 6 years is perfect for a small frame of the same age - 7 years ditto - against by the 7-8 years is more suitable for a child of 8 years for mine 7 years which is very thin in fleet bust level but much belt-tightening in the back the default disappears. Parcels received in 2 weeks and quality / price very satisfactory.