Sometimes any waste they havenn't gotten rid of can be felt as lumps if your not used to what your looking for as well. Just relax and let her have some quiet, if she is gravid she will lay soon enough. First time around it can take them a few times to get it right with the digging...mine dug for days before they were happy enough to lay, just make sure you keep the sand wet and comapcted for her.
Mine don't use a laybox btw - I just remove the males from the tanks and give the girls plenty of sand.