A 12 month old female Veiled could certainly be laying infertles, but if she was recently housed with a male since I know you recently got her she could have fertile eggs.
I guess it is good that you have sand that she is digging in to indicate this, however you should not have sand or any substrate on the bottom of the cage. They need at least 10-15" of sand in a large container 10-15" around to dig in and lay eggs. Can you take the sand out of the bottom of the viv-put it in a bucket the size that I mentioned it, then moisten the sand so that she can dig a tunnel. Sand needs to be moist enough that she can dig and the sand will not collapse as she makes this tunnel. Also have a branch or something running down into the pot or bucket so that she can get in and out.