Since Rosie loves Little House so much I had to find her a sunbonnet. I got an amazing deal on a e-bay auction for this brand new one from Old Fashioned Clothing. They have all sorts of "prairie wear" for young and old. Amy was sweet and helpful, and they shipped it out pronto. Check it out!
BTW, they have smaller bonnets, but the auction was for a bonnet for ages 4-12 and I figured she'd grow into it. :^)