Pediatricians? Wait? How old is she? (I've been reading about pediatric MS)

The reason that you dont give ORAL prednisone with optic neuritis is because they did a study years ago to see which worked better for treating ON (optic neuritis), oral or IV pred. It's called the Optic Neuritis Treatment Trial.

The study found that people who got oral prednisone tend to have more relapses of optic neuritis than people who who treated with IVSM (IV solumedrol, another form of prednisone) or for people who just waited out the symptoms of the optic neuritis without treatment.

Because of the chance of getting relapses of the ON if you take oral prednisone, that's why doctors tend to prefer to give IVSM, or just wait it out and let the ON resolve naturally. (which it can do. First time I had ON, I waited it out...took about a year, maybe a year and a half for me to recover from that. I'm back to about 95% or better. I can see colors again! yay!)

How bad was her optic neuritis? Was it both eyes, or just one? How much of her vision was affected? Was her color vision affected?

The reason they use contrast (gadolinium) is to make any lesions in the brain matter "light up" under the MRI. Makes it easier for them to see if there's anything wrong. I know that lesions CAN be seen without them. One of my MRI's that I had, they screwed up and couldnt get any contrast into me. Still had a lesion show up on the MRI, so they made me come back a week later and do it again. (and you know what? they make you pay for the MRI even if they screw it up...that hurt, paying for two MRI's that year)