The colorful Ribbon Braid Hat with Extra-Large (7-inch) Brim is from The San Diego Hat Company. A spokesperson for the company says that Sandra regularly shops Fedora Primo in Santa Monica, CA, which carries the popular brand.
The particular hat is from the 2007 line and sold for about $30. A new version of the hat is currently online with a different color scheme. Other styles have a smaller brim and similar colors.