We took a fat quarter, pinned on a couple of ribbons (we should have sewed them down but oh well) and folded it right sides together. We pinned it. Then I used a fabric marker and drew a line around the edges at a 1/2 inch for her to use as a guide.
She used the sewing machine and very carefully sewed along the line. She did awesome - better than I do most of the time (granted I am a beginner myself). We used a box to make the pedal a bit easier for her to use!
She turned it right side out, put in the stuffing and together we sewed closed the opening.
She is so proud of her new butterfly pillow! Pretty good for a 6 year old!!!