Making a Tinkerbell Costume

Depending on the size of your daughter you could make a very simple dress from a pillowcase. Just cut head and arm holds. Then zig-zags to make ragged edges around the bottom. Dye the pillowcase green or light purple, if it's not already. Add a belt to gather it at the waste. You could use craft foam or even a sash. Add some tights and make some foam shoe covers that tie behind the ankle or just use ballet slippers.

Why not modify a dress from goodwill and add netting, sequins, beads etc. Glue on instead of handsewing and find a good picture of tinkerbell with wand to refer.