It's all knits, but they vary a bit in type. There are 3 nice cotton jerseys (though the magenta is a really heavy one). The pink floral top is a slippery, poly blend with very little in the way of stretch. The dress is a lycra blend with lots of stretch in all directions, for a sporty feel, which makes a great play dress.
If you look carefully, you'll see that she posed her toy dragon for each different shot. He was her "accessory".