I love vintage hats, and recently I found this site called :
http://www.etsy.com
And ordered 5 vintage hats,
I have noticed that my head gets cold very easily with or without hair so I buy lots of hats.
There is alot (over 500) of cute handmade knitted hats for kids and adults : go to the site and on the top you will see a scroll bar saying: Handmade Items: Tags, titles, : and just type in hats next to it and click search.
And for vintage hats go to the site, click on buy at top of the screen, it will bring you to a page that has a bunch of search sections, click on the top bar that says categories, Next scroll down the page and find the Vintage link, click on that and it will bring you to the vintage page, then click on accessories, and under that you should see hat. Once you are there I would click on the price button on the right corner of the page and it will weed through all the hair accessories so you don't have to scroll through so many pages. At first it will list the really expensive ones but don't worry the prices will go cheap!
Hope this is helpful and you find something you or your kid likes!
xoxo Francie
Below is a picture of me in a vintage faux fur hat, fun!