The hat looks good! What size yarn and hook did you use? I've not made anything for my dolls yet because I've been having trouble finding small enough hooks/needles.
Actually that's the beauty of it! I used a size F/5 (3.75mm) hook and "regular" yarn for it. Caron Simply Soft. By regular I mean just the kind you see hanging around Walmart and such. I'm not knowledgeable about yarn types but I believe it was worsted yarn.
I have trouble finding patterns that don't require you to use a tiny yarn and like 3strands of sewing thread wrapped around itself x_x, and most were for girl dresses and things.
Edit: I just tested the pattern I wrote with the second cap, looks the same, so posting pattern above so nobody else has to share my frustration when trying to alter a human sized pattern. I am not good with numbers, shrinking, ect.