I used this book. How adorable is it! It has newspaper cuttings in it from 1968
I chose this adjustable Sun Hat pattern because it will fit both girls
I made quite a few changes though. I used interfacing instead of the reommended Canvas and I lined it, although I didn't have anough of the butterfly material so had to pick another colour from the stash. I widened the brim considerably to provide more sun cover, I changed the way Enid suggested sewing a fold for the ribbon to go through and I used sew on velcro rather than metal hooks to help make it fit better. So, a 2010 version!
Overall I am really happy with it. It is really adjustable, fits well and doesn't come off unless little hands give it a pull. Next time I will use a stiffer interfacing and make the whole thing slightly larger to get even more wear out of it. I love that it fits both my girls.