If she was mated before the last set of eggs was laid she will likely have retained sperm and part (or all) of the next clutch will be fertile.
If the last clutch of eggs was infertile (because she wasn't mated) then I would wait for her to lay the next clutch and then, for a few days after she lays it, water and feed her well to let her recover from producing eggs. If that clutch is over 30 eggs, I would then cut back on the amount of food you give her. (If her clutches were less than 30 you don't really need to cut back what you would have normally fed her...just go back to what you were feeding her before.)You don't want to starve her, but you don't want to overfeed her...this should keep the size of the clutch lower and help her to live longer.
You asked..."how often should I breed my veiled chameleons knowing that the girls not egg production is my primary concern ? I don't want to endanger thier health but one of my girls is showing her colors again and she layed once early this year already"...when I control the food and temperature once my females are mature, my veiled females don't produce even one clutch of eggs until I mate them. I have several females right now that are over 3 years old that have not laid a single clutch. The last one that I lost was over 7 years old, had produced no clutches until she was over 3 and then I mated her. She produced several fertile, infertile and partially fertile clutches after that (depending on whether I mated her or not) and didn't stop reproducing until she was over 6. Her babies were all fine. In addition to controlling the food, I keep my females SLIGHTLY cooler than the males. It takes some know-how to get this right...but most of my females live to be over 6 years old keeping them this way.
Hope yours will live for a long time too!