Fertile bearded dragon eggs should have a purplish reddish spot, a little smaller than a dime. Chances are you won't see the act unless you spend a lot of time in the same room as them. It is much quicker than with ball pythons. Unless if Delilah is quite old, I would be surprised if the eggs weren't fertile. They will dry out quickly though so you have to pick them reasonably fast or they won't be viable.