using bricks is a good way, 2 bricks set up in a corner of tank in an L shape.
Meaning with the back and 1 side being the tanks glass, and the bricks being a side and front, with a little opening, or space between brick and glass for an enterance for her, to get in and out. Put a flat rock or roof on your squared nest!
I use a piece of slate for a roof, but anything sturdy and flat.
Fill the square with about 3-4 inches of dampened sand.
Sometimes they choose to dig and lay somewhere else, (they can be fickle) but hey shes a mom to be so ya have to make things they way she wants, hehehehe.
If she decides to dig somewhere else just dampen some sand and put it in a corner, or where she wants it.
I find that if you put her in the nest a couple times show her the enterance, they will use it.
Also your boyfriend makes a good point, IF they dont feel as though they have a suitable place to lay they sometimes wont!
I also, would NOT heat the eggs with a lamp heating them from above. My opinion, it can be very drying. It is usually done by keeping in a container either in a room where the temps will not go below high 70's or above 90.
Or a regular incubator, or I have heard people sitting the egg container On top of a fish light, and heating from bottom (ask JohnE about that)
But never under a hot lamp ! Others may want to comment about that.
Hope Splash does fine 
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Eve