Jajeanpierre is right...many female veiled chameleon female's die from reproductive issues. With proper care you can usually/often prevent this.
Overfeeding the constantly can push them to producing page clutches, push them towards MBD and constipation and even prolapsing. IMHO it's better to go a little slower to grow them than too fast. Veiled chameleons can produce eggs even when not mated so it's important to have a proprer egglaying site in the cage so they can dig to show you when they are ready.
I use an opaque container at least 12" x 8" x 8" deep filled with moist washed playsand. Some will not lay in this size bin so they can be moved to a larger bin once they are ready.
Well fed/gutloaded insects and appropriate supplements are important too.
I feed/gutload the crickets, roaches, superworms with a wide assortment of greens, veggies such as dandelion greens, collards, kale, endive, carrots, sweet red pepper, sweet potato, squash, zucchini, etc and a bit of fruit such as Apple, pear, melon, berries.
Since most feeder insects have a poor ratio of calcium to phosphorous it's recommended that you dust the insects just before feeding them to the chameleon with a phosphorous-free calcium powder to make up for it.
You need a proper UVB light to allow the chameleon to produce D3 so that it can use the calcium in its system. Since it's not certain that a chameleon gets enough from the UVB lights used we recommend dusting twice a month with a phosphorous-free calcium/D3 powder to ensure it gets it without overdosing it. D3 from supplements can build up in the system and lead to MBD so we only do it twice a month and leave the chameleon to get the rest from the UVB light. As long as the chameleon can move in and out of the UVB at will it won't produce too much D3 from the light.
We also recommend dusting twice a month with a vitamin powder that contains a beta carotene (prOformed source) form of vitamin A. Vitamin A from prEformed sources build up in the system and lead to health issues...so by using this type of vitamin powder it leaves it up to us to decide if/when the chameleon needs it. There is controversy as to whether all/any chameleon s can convert the beta carotene.
When the female is getting close to laying she will become plump, roam the cage looking for a laying site, drink more, likely eat less.
It's important not to let her see you watching her while she's digging. It's said that seeing the male can push her into producing a clutch too.
IMHO two veiled chameleons should not be kept in the same cage and I don't even put the cages so they can see each other.
I hope this helps! Hope I didn't miss anything!