While it is never good news to hear that a dog doesn't know where her legs are; the one silver lining of that is that we know that her legs are not actively causing her pain. If they were, she would be focused on them and in some cases dogs that are painful will mutilate the legs as if trying to attack the pain (not knowing it is part of them). So, her demeanor alone doesn't suggest that she is in pain with this.
Furthermore, with that breathing rate (which ~30bpm is normal), we also can tell that she is not a dog in distress with pain. In regards ***** ***** hiding, this is more likely a result of defensive instinct (where if one is vulnerable it is better to hide then let the world know and thus make you a target for predation). So, while that is her telling us that she knows she is compromised, her ability to settle along with every thing else doesn't make me suspicious of pain.
With all this in mind and her treatments at this stage, I don't think she is a dog in discomfort. Instead, she sounds like a dog that may be confused and feeling vulnerable due to not understanding where her leg function has gone. In regards ***** ***** and her future, I would say that it does depend on how long you have treated already (since nerves do need time to respond since they are the slowest to heal tissue in our body) and how severe those xray changes were. If they were very severe and her vet feels that her prognosis is poor; then we may only be able to trial treatment for a few weeks to see if we can help her regain use of her legs before considering letting her go. Otherwise, if your vet is cautiously optimistic with what has been seen, then longer could be given. Or if the vet was more suspicious of a possible spinal based issue (ie disc, blood clot, swelling, tumor, etc), then you could also consider an MRI if you wanted a definitive diagnosis to what is causing her signs to determine if there are any other options for her (ie surgery).
Overall, I don't think she is painful here. Instead, I just think she is unsure about her world with this sudden loss in her leg function. So, it does depend on how severe those xrays were, but it is worth trying the treatments you have her on to give her a chance. Further to this, I'd just note that it may also be of benefit to start her on some anti-oxidants (ie Vitamin E, Omega 3 + 6 fish oil) and also do some gentle passive range of motion on her back legs if she will allow. That way you can slow any muscle
atrophy she may develop from not using her legs. To do this, I would note that you can watch a wee video on passive range of motion @ https://www.youtube.com/watch?v=V6fOuQ_W4vo
Please take care,