Simplicity 2872 for Grace's third birthday. It's an easy pattern, but I discovered that I don't particularly enjoy cutting out tulle and satin - especially dozens of pieces. However, it was certainly worth it in the end.
The wings are made with chenilles sticks sewn onto the wing fabric. It doesn't work very well because chenille sticks are too bendy. It would have been better to use a stiffer wire and to outline the wing with something.
She'll wear this costume all day sometimes, which makes me glad polyester satin is machine-washable.