Problem is, you tucked the letter and included shopping list away with other pieces of mail.
Go ahead and jump ahead of the Sorting Hat's announcement and get your child outfitted in a set of these exclusive Gryffindor Robes. Now it's almost September and you want to avoid the packed streets and shops of Diagon Alley, but your child needs his 3 sets of plain, black, work robes in a hurry. Luckily, the wizarding world has caught on with modern times a bit, and have helped some wizarding shops, like Madam Malkin's, get a selection of quality robes online.