5year old female with back pain and fever of 105
She needs to be seen now.
Your daughter may have a urinary tract infection that may be involving the kidneys. This would cause back pain (especially in the flanks) and urinary pain and fever.
This is a very high fever, and a kidney infection, if that is what it is, needs to be addressed immediately. I advise you take her in to the ER now.
I would be happy to provide further information as needed, but I don't want to delay your taking her in to be seen right now.