Lizards shed in patches, not all at once like snakes. They shed in patches,and areas are shed at different times, for instance, she could be shedding her front legs one day, or her back and tail another week. One of the areas that lizards shed is their heads. The nostrils com out like little plugs. Humiditiy aids in shedding. If the enclosure is too dry, skin can become stuck. If it gets stuck around a tail, toe, or limb, and you can't get it off, the tail, toe or limb will fall off. The tail NOT grow back on a chameleon, and if it does fall off, you must watch for infections, which spreads easily in such humid environments.
Veiled chameleons are one of the hardiest chameleons available, and they are also the easiest to care for. She looks very well-nourished in the picture, and I hope she looks like that for a long time.
see http://www.veiled-chameleon.com/care-sheet.html for how to sex your veiled chameleon.
it is a great veiled chameleon forum