Immediately.
The longer they stay in the more the eggs "settle".
Freshly laid you are less likely to disturb them, as they start to form capillaries you can kill an egg if you cause too much upheaval to it.
It is not a particularly good idea however to incubate/hatch them unless you are specifically breeding high end morphs and have the equipment, time and space to look after the hatchlings.
Bearded dragons are hugely over-bred and the market is flooded, they are costly to raise, require multiple feeds every day and daily cleaning. You also cannot keep them all in the same viv as they will bite each others toes/tails off. Anything that moves is potential food.
If those eggs are fertile you will likely find that she will also produce more clutches almost immediately following the first clutch being laid, with about 6 weeks (in some cases sooner) before wanting to lay again. Its not uncommon for 5 clutches or so, with 15 to 20 eggs in each.
The most effective way to kill the eggs is to freeze them, once shes covered the site the beardie wont care about the eggs anymore.