oh no, my friend has a smallish head (20"). My head measures 23" which is quite large, and look how it fits me. Even if I roll it up, it will be too big for her.
So! I can keep it for myself, to wear wtih my heavier winter coat in January. I don't think it can be de-knitted, cuz of all the knotty bobbles in the yarn. I do have another ball.
But I don't know how to figure out how many stitches to cast on for a smaller head.
I'm thinkin': the yarn knits about 5 stitches per inch, so a 20" head should need 100 stitches. BUT: this hat was knit with only 60 stitches and look how big it turned out. Maybe it's the needle size?