Welcome to the forum!
In addition to other comments...veiled females can lay eggs even when not mated so once she is about 4 or 5 months old, there should be a suitable place in the cage for her to dig to show you that she needs to lay eggs. Failure to provide her with a place can lead to eggbinding and eventually death.
Appropriate temperatures aid in digestion and thus play a part in nutritent absorption.
Exposure to UVB either from an appropriate UVB light or direct sunlight allows the chameleon to produce D3 which allows it to use the calcium in its system. Neither source of UVB should not pass through glass or plastic.
Its important to dust the insects before feeding them to the chameleon at most feedings with a phos.-free calcium powder to help make up for the often poor ratio of calcium to phos.
I also dust twice a month with a vitamin powder that contains a beta carotene (prOformed) source of vitamin A. Beta carotene won't build up in the system like prEformed sources will. However, its not known if all/any chameleons can convert the beta carotene so some people give a little prEformed vitamin A once in a while. Excess prEformed vitamin A can interfere with the D3 and push the chameleon towards MBD...so don't overdo it.
I dust twice a monthe lightly with a phos.-free calcium/D3 powder. D3 from supplements can build up in the system, so be careful with it too.
Gutloading/feeding your insects a good diet is important too. You can gutload/feed crickets, roaches, superworms, etc. with a wide assortment of greens (dandelions, kale, collards, endive, escarole, etc.) and veggies (carrots, squash, sweet potatos, sweet red pepper, etc.).
A veiled can also be given the above greens and veggies and a small amount of fruit (apple, pear, melon, berries, etc.).
Here are some good sites...
http://adcham.com/
http://web.archive.org/web/20060502...rnals.com/vet/index.php?show=5.Vitamin.A.html
http://web.archive.org/web/20060421.../index.php?show=6.Vitamin.D3.and.Calcium.html
http://chameleonnews.com/?page=article&id=102
http://www.uvguide.co.uk/
Hope this helps!