Hello there. You can try feeding her phoenix worms (BSFL - Black Soldier Fly Larvae) as a regular staple to her crickets. They have a great source of calcium and they wiggle enough to get their attention too :lol: She does look like an alert happy little thing though, so that's good. As for your T8 light fixture comment, no, they cannot just go in any fixture. They make specific T8 and T5 fixtures. The T8s are thicker and are your common size run of the mill fluorescent bulbs you see in most places. The T5 are smaller, but they pack more of a punch. I would make sure that whatever fixture you get has a reflector for the bulb so the little one gets all the UV she can. I think some make reflectors out of foil, some use reflecting tape, or some buy the reflectors that clip to the bulb.
When I first had my beardie, I had her in a tank much like yours. I bought a substrate made by Lugarti and specifically designed for reptiles. It was special blend of high quality sphagnum peat moss, extremely fine sand, and bentonite clay. I bought tons of that and packed the bottom of the cage to make it shorter in case she did fall or jump, she wouldn't hit the hard glass, she'd hit soft dirt. My brother uses it for his baby beardie and the little guy is doing fine jumping around here and there.
Good luck with your little one! Let us know if you have anymore questions!