Since your girl hasn’t laid eggs before, I just want to give you some advice and info on how it goes and what to do.
One morning you’ll find your girl has started digging. It is absolutely essential that she is not disturbed for anything less than the house being on fire - seriously! I would suggest getting things ready by covering up at least the lower 1/2 or 1/3 of your enclosure with a light cotton cover. Do make sure to leave most or all of the bottom service door uncovered for proper air flow. This will provide her the sense of security that she needs to be able to feel comfortable enough to lay her precious eggs. She doesn’t know nor care that they’re infertile. Anyhow, once she starts digging if she sees anyone or is made to feel unsafe, she will stop digging and risk becoming eggbound. I cut peek holes in my cover sheet so I can monitor without being seen. Once she’s digging, no need to worry about feeding her. You can set up a dripper if you don’t have an automatic mister, but make sure it isn’t going into the bin. She may dig a few test holes until she likes one. Then she’ll dig all the way down and usually against the side, turn around and lay her eggs. This takes time and she may sleep in her tunnel. When she’s laid all her eggs, she’ll carefully cover all holes and once there’s no sign of anything, she’ll return to her basking branch. The entire process can take a couple of days. When she’s done, feed and hydrate her very well for a couple of days. Then you want to start her diet of 3-4 feeders, 3 days a week and keep her basking temp no higher than 80F. This will help reduce her egg production and laying, which will help prolong her life.
Signs that there is a problem - she starts and stops digging in various places and over several days with no real progress. She starts dropping eggs here and there. She stops eating, drinking and is lethargic, sitting on the bottom of the enclosure. She has her eyes closed during the day. Looking like she is straining. Passing blood. If you notice any of these, she will need to be taken to a good vet without delay. The longer you wait, the weaker she will become. Make sure to know what vet in your area sees chameleons, has experience with them (especially egg bound ones) and you know what their hours are.
I know I’ve thrown a lot of info at you right now, so do ask any questions you may have.