I kept thinking this was Sirius, because Alf reminded me of Alphard. Lol. But I know it isn't :) Poor Sirius didn't have such a grandmother, who sounds more the Molly Weasley type than the Black kind.

Lovely poem again. I love the images that you present here. This entire stanza was such a joy to read:

Salt on the window, nails in the lintel,
Red rowan’s twigs our fire to kindle,
Clothing reversed to show off its stitches,
Milk at the door to placate the house-elf,
Collections of bells along the high shelf,
All to ward off nasty fairies and witches.

The last stanza is, of course, the best! I am running out of words to praise lol. Really loved it.