honestly i just went through this with my panther and mike gave me the best advice possible....
just leave her the the f alone.
make sure she has plenty of water and put her cage somewhere with very low traffic, the less you f with her, the faster she will start digging and lay.
once she starts digging, although its tempting especially if you have never experienced it to try to sneak a peak or check on her, like i said just stay away
i can now tell u this from experience, you don't want to spook her watsoever, in the wild the object is for no predators to see her lay so they try to be very secretive about it.
if she starts digging, she will almost certainly lay, even though it make take all day. just let her do her thing, she'll do it, chameleons are smart survivors, they don't want to die and as long as you give her plenty of cover and make sure she can't see people or pets walking by she'll dig, just make sure your container is deep enough but not too deep