this reasearch should have been done befor you bred your chameleons in the first place but anyways,
15 to 40 days after mating she will lay her clutch of eggs so put a lay box in there now so she can get rid of those eggs cause if not she might become egg bound and die , so make sure you have a lay box that is big enough to hold her and the dirt she will move to make her tunnel and you cannot bug her when she is laying her eggs or she will think you are out to get her and her eggs and will not dig and possibly die from egg binding
Take boothy's advice and put an egglaying container in the cage so that she has a place to dig. If she has no where to lay her eggs, as boothy said, she could become eggbound and die. Also...don't let her see you watching her when she starts digging or she will abandon the hole. If she does it often enough it can lead to eggbinding too.
Have you got a place to incubate the eggs and a container to put the eggs in ready for when she lays them? I always let mine finish burying the eggs and wait until she has gone back up into the branches before I dig them up. I incubate mine at about 78F. I place them in a shoebox sized tupperware type container that I fill half full of slightly moist vermiculite. If you take a fist full of the vermiculite, you should only be able to squeeze a drop or two of water out of it. I lay the eggs in rows in slight dents in the vermiculite. I punch two very small holes in the lid and put it back on.
Dig them up carefully and try not to turn/rotate them as you move them to the container that you will incubate them in.