Hi. If you are bringing her home on SubQ fluids that you are doing daily, that's great. That is exactly what I would have suggested. The SubQs continue the good work the IV fluids have done. Ideally, SubQs should continue for several weeks to several months, depending on blood level results. Blood testing is best done every 2 weeks for the first month, and then 2 monthly if things settle down.
SubQ fluids should be Lactated Ringer Solution, unless there is a very specific reason your vet doesn't wish to prescribe this. I can assess the correct amount you should be giving daily if you provide me with your dog's weight.
The bloody stools are of some concern, as this suggests a rupture (possibly from ulcerated gastric tract or stomach). Has your vet given anything for this? The other issue this might cause is anemia through blood loss. Do you have the blood test reports? If not, please ask for them and post the RBC (red blood cell), WBC (white blood cell), Amylase, Phosphorous, Calcium, Potassium and Sodium levels.
Did the vet undertake a blood pressure reading? This is crucial in kidney disease. If the blood pressure is abnormally high, medication to treat it is important. Ideally, this should be either Benazepril or Enalapril.
Diet restriction of sodium and phosphorous is also important. At stage 3, there is also some advantage to minimizing protein to some degree (about 15% of total food intake daily). Nausea is very common (due to the toxins in the blood and stomach), so anti-nausea medication is advised. Cerenia is a good one.
Dry dog food (including prescription dogs foods) are best avoided, as they can dehydrate dogs, which is the last thing you want at this stage. Canned kd food is better, Hills kd for example, as this contains 80% water and is a good way of helping rehydrate and flush toxins.
Water at home is best given as Filtered from either a faucet filter or bottled. This has less chemicals in it and is devoid of sodium, so easier for the kidneys to deal with.
That's probably enough for now.
Get back when you can and when you have some updates.
Tony