first of all the 30gal tank is not big enough for an adult dragon. minimum size should be 4x2x2 in feet. some people tend to think their dragon is doing fine in a 30 or 40 gal, but truthfully they are not. i used to be one of those people when i first started.
as for her pacing and digging and not eating alot, she may have eggs in her and cannot find a good place to lay them. females do not need a male to produce the eggs, the females do that on their own. a male is just their for her sperm to fertilize their eggs. and a one time mating session can fertilize 3-5 clutches, sometimes more sometimes less. females usually stop eating for a few days before they lay their eggs, starting digging themselves a lay hole, and are pretty lazy other than the digging.
heres what you need to do. feel her belly and if you feel marble like objects, those are eggs.
soak her in a warm bath first then do the following. this will ease some stress and get her hyrdated as well.
get a large rubbermaid container or another tank/cage.
i use a plain potting soil*nothing with plant food or insecticide added* with some vermiculite as a laying substrate.
dampen it so it is nice and damp but not soaked. you dont want it to be dry but you dont want it like mud or anywhere close.
pack down the moistened substrate, having about 15 inches in height at one end of the lay bin. i usually make like a ramp with the substrate.
and put your female in their with heat and UVB and watch her closely for a couple days. should not be long if she does want to lay. if she does not lay within 2 days and you have felt the eggs in her belly then get her to a vet asap
other than this, only other thing to do would be a vet check. but it sounds to be like she may be gravid and she needs to lay the eggs. if she does not it can harm her and kill her. eggs will rupture in her ovaduct, called egg binding.
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Beach Beardies
2.4. bearded dragons
1.0. Turquoise x Sunburst Veiled Chameleon
1.1. Sugar Gliders
0.2. Felines *queen athena and missy*