After watching me do this for years, she knew how to make the pattern - just trace a dress you like. At first, she brought in a super cute shirt-waisted dress which I quickly pointed out was a wee bit complicated and needed a million pieces which is why I always make her the same style of dress. She understood and brought back a dress I had made for her last year.
She found a nice polka-dotted vintage sheet and got to work. For the seam allowance, the width of a ruler was added to the sides and shoulder seams. Next, she cut out her fabric and sewed it all up. I helped to iron the hem. After sewing the hem and declared that no, she didn't need to finish the neckline and arm holes. It was just fine the way it was.
It could use a little art work, though. Using permanent markers, she wrote her name and drew a lovely picture. Phoebe wore it for dinner where she proceeded to get spaghetti sauce on it. Ah, to be 6!