HI Sheila; 
Don't ya wish we could move like this little man does? 
I'd be in traction if I tried! I wish I would have seen your post earlier but maybe I can still give you my experience with Prednisone.
I have OsteoArthritis, FM, Crohn's Disease and a few more things wrong with this old body. I've taken Prednisone for my Crohn's and when I'm on it my body feels great. I have a lot of side effects from it, not all good, but all the aches and pains in my body disappear. My normal starting dose is 40mg per day for about 1-2 months or until my Crohn's is under control. Then I begin a very slow reduction. In spite of it's side effects, Prednisone is my miracle drug. It's the only thing that can bring my flare ups under control. To be honest, I wish I could take a low dose of it for my Arthritis and FM. Some days I hurt so bad I just want to fall alseep until this nightmare is over or they found a cure!
I'm going to guess that between the unbelievable stress you were under, with your daughter in the ER, and the "not made for human beings" chair you had to sit in for so long even the Prednisone couldn't hold back the pain. It does have it's limits. If you had to miss a dose or two because of your time in the ER, it's possible that your body needs to "catch up" on the Prednisone affects. I'm hoping that by this time you are feeling much better. I know once my back becomes very painful it sometimes takes days before I get back to normal.
I hope everything is okay with your daughter. Hospitals can be such frightening places when your child is the sick one.