Part out a box on top of her head and split it in half diagonally. Put the half towards the back of her head in an elastic.
Split the front section in two and tie a knot like you are starting to tie a shoe.Bring both ends back to the elastic and secure with another elastic over the same spot.Add a cute bow. This one came from Kayte Bug Boutique.
I'm guessing this hairstyle would work for short hair as well!