The steroids didn't hurt her. Prednisone is a standard steroid that really does help the dogs with back issues get back up on their feet again. It sounds like her back was getting ready to go out, and it just so happens the shot was there in the middle of it. It didn't cause the problem, it wasn't a bad reaction to it or anything. It was just that she was at a point in her injury where the injury couldn't turn back.
I would recommend to keep on with the laser treatments, acupuncture, steroids, and crate rest. The combo has helped MANY of the doxies in the group get back up on their feet and walk again. (They could throw in some pain meds, too.) I have watched at least 10 dogs in this group go through this in the past 2 or 3 years, and they all are back up on their feet and walking again (without surgery).
5 Elements in Omaha (I know you're from Lincoln) does do holistic, but they also would put them on steroids when there's a disc injury like this. It's just one of the few drugs that actually helps.
I do know some vets recommend anti-inflammatories (like NSAIDS), but the dogs that took those first didn't get better, and ended up switching to steroids.
Keep us posted on her progress, but it does take time for them to get better. You have to have patience, and keep her on strict crate rest. No jumping, running or playing when she does start to feel better. (And she will!)