Jacksonii are born in an embryonic sack, just like puppies. The female jackson usually drops the sack from some height in order for it to stimulate the baby into breaking out of the sack. I have seen female jacksons aim the drop over a large leaf and manage with good accuracy. If the female doesn't have an idea spot, she may just commence delivering - thereby you will find babies who were unable to escape the sack.
Now to the neonates: Baby jacksons eat close to 5 times more in the first 24 hours of life than most other species of chameleons. These tiny eating machines will walk great lengths looking for food. If you had no small crickets or fruitflies to offer them, you are most likely in for more deaths.
Jacksons need foliage - for many reasons. Provide them with as dense as possible mini-jungle for their home. Use china doll, house ivy, small ferns, creeping fig; hoya plants and other small-leafed, smooth plants.
If you do not have a fruit-fly proof cage, you can use a tub and place fabric mesh over it. You can get this mesh at any fabric store (even Wal-Mart or Target) and it is inexpensive. Just ask them for netting, and the clerks will show you the different kinds. If you want to use 5 gallon buckets, you can purchase paint strainer bags at Home Depot - they will fit (upside down) over the bucket and form a mesh tent.
Use hydei flies (melangaster are too small to interest the jacksonii) and 1 wk crickets. Do not dust them for a few weeks - as jacksonii are sensitive to supplements. To keep the flies near the chameleons, purchase wooden skewers (in grocery store - oriental food section) and spear small wedges of orange on them. Be sure to hid pointy tip in orange. Stick those in the soil of the leafy plants that you are using - instant dinner plates.
Mist them several times per day. Use a fine mist so that it beads up on the leaves. Use warm, non-chlorinated water (be sure mist is warm). The babies need humidity.
Jacksonii usually only deliver once per year (every 9 months), so you have time to prepare for next time. The death rate for jacksonii is highest in the first few months of life.
Hope this helps some,