Hi...Sorry about your dragon. Make sure you do as Tracie says. Even if you need to put your girl in a rubbermaid type container...make sure to keep them separate.
Fix her a nesting box and put it in one end of her tank/enclosure, just in case. Get some Bed-a-Beast or something similar. I usually mix it with some playsand (from Home Depot)... NOT reptile sand. I use a rubbermaid type tote about 12" x 16" X 6"-8" deep, with a lid on it. Cut a hole larger than she is on one end of the lid. Dampen the soil and tamp it down a bit so it won't cave in when she digs her hole to lay the eggs. If you are planning to hatch them, you need to get an incubator. Some people make their own incubator. Google it if you decide to do that. Check the sand daily and keep a watch on her. They often will make test holes before laying the eggs...could be as many as 30 something eggs!
How often do you dust her food? Might want to dust it 5 days a week, once a day for a while til you know if she is gravid. Sometimes you can see the eggs thru her skin.
Good luck
Patsy