You could, but honestly I wouldn't do that right now, I don't think it's at all necessary as long as you get her lights set up properly and her temps correct. I've always used a 40 gallon breeder for my dragons at a month old, and she's older than that, so I think the 40 gallon breeder is fine. Plus, it will be much easier to get the temperature gradient correct, as you already had it correct to begin with. I think once you get the Reptisun 10.0 T8 UVB tube away from the back center of the tank and get it over the Hot Side and right alongside the basking bulb, and get some more light/heat on the Cool Side, she'll perk right up. Just looking at that photo you can tell that she's gotten little UVB light at all if she's been spending much time on her basking rock, there's no metal reflector and it's no where near her Basking Spot.
I would first move the UVB tube and attach it to the underside of the mesh lid on the Hot Side, right alongside the basking light, mover her basking rock right directly underneath both of them together so she gets both lights at the same time, then I'd order a slip-on metal reflector (18") on Amazon ASAP, they don't cost much and they really are a necessity. But just getting that UVB tube over her basking spot is going to help pretty quickly. Again, make sure that her basking rock is high enough to put her within 6" of the UVB tube, check your temps again once you get it all set up correctly, and be sure to let both lights on for at least 13-14 hours every day. I think even by tomorrow she'll perk right up.
Be sure to turn both lights on in the morning for at least 1 hour before offering her any bugs, she won't be much interested until she warms up and absorbs some UVB light. The lack of UVB light really does cause serious issues quickly. But no, don't cut the tank in half, at least not until you try it with her lights set up correctly. Give that a week and if she is still acting lethargic and not eating then you could try it, but I don't think you'll need to at all.
I would first move the UVB tube and attach it to the underside of the mesh lid on the Hot Side, right alongside the basking light, mover her basking rock right directly underneath both of them together so she gets both lights at the same time, then I'd order a slip-on metal reflector (18") on Amazon ASAP, they don't cost much and they really are a necessity. But just getting that UVB tube over her basking spot is going to help pretty quickly. Again, make sure that her basking rock is high enough to put her within 6" of the UVB tube, check your temps again once you get it all set up correctly, and be sure to let both lights on for at least 13-14 hours every day. I think even by tomorrow she'll perk right up.
Be sure to turn both lights on in the morning for at least 1 hour before offering her any bugs, she won't be much interested until she warms up and absorbs some UVB light. The lack of UVB light really does cause serious issues quickly. But no, don't cut the tank in half, at least not until you try it with her lights set up correctly. Give that a week and if she is still acting lethargic and not eating then you could try it, but I don't think you'll need to at all.