Upload & Sell: On
If I were to try this, without any additional gear other than my camera, here's how I might do it:
I would look for a location in full sun, but with a darker, inobtrusive backdrop (maybe a hedge or a wall). I would position the subject so that she is somewhat backlit by the sun, but not in full silhouette. Pose her carefully, so that the sun still illuminates the face, but there's a pleasing shadow on the camera side of the nose. For example, if you use a clock analogy, you're at six o'clock, she's in the center of the clock facing four o'clock, and the sun's at two o'clock). The background should thus be in full shade. If she then blows the glitter from her cupped hands, it should sparkle in the sun. Take a few tests before she blows the glitter, and meter off of her face to get a good exposure, or the darker background may result in an overexposure of her face. Shoot at a relatively wide aperture (say between 2.8 and 4.0 if your lens can do that) to throw the background out of focus and freeze the glitter in mid flight.
That should get you close. Have fun, and let us see the results!