0.4 lbs is 181grams. We feed between 5-7% of the body weight each feeding. At 181g that would be between 9-12g so you're pretty much on target. At 9 weeks I would feed every 6 hrs and she would probably work up to 10% of the body weight which is 18ml.
She really did need the Ciprofloxacin for the AP. She wouldn't have survived without it. With that said, Ciprofloxacin can cause some serious side effects. I will say that we have not seen side effects from Ciprofloxacin when used for squirrels but of course it's possible. The more notable side effects are the central nervous system, ligament/joint issues and cardiovascular. The pounding heart can be caused by Cipro but in Bea's case we can't say with certainty that it caused this. There might be other issues. The symptoms should subside if it was the Cipro but again I don't know if it was related. This will probably be a watch, wait and see sorta thing.
We don't know the extent of the spinal injury causing the paralysis. We also don't know if she had a head injury and is neurologically compromised. So many unknowns but I wouldn't use Cipro in the future as a just in case. Neuro babies shouldn't receive Cipro anyway as it can cause seizures in those prone to them due to a head injury.
Often paralysed babies can benefit from prednisone but with her other symptoms I would be afraid to use it. I hope for the best for Bea as I can tell that you are emotionally invested in this little bundle of love.
Please let us know how she does. I wish I knew more to tell you but I really don't know what to think here.