Dearest Narcissa
I thank you for your lovely words of comfort. It upsets and angers me that a son of mine was placed into Gryffindor, that house of Mudbloods and filth. However, this does not mean that we give up hope. I am sure Sirius is also lamenting his disastrous Sorting. Please make sure he writes to me. I hope that you are having a pleasant time at Hogwarts.
Your dear Aunt Walburga.