Medical info

What is the name of your state (only U.S. law)? Pennsylvania
My sister has power of attorney for my mother; if my mother becomes incompasitated will I be able to get information regrding her condition from her doctors/hospital etc. or will it only be given to my sister?

You probably will not be able to get any information without a HIPAA Release and/or some form of Medical Power of Attorney (also known as a Healthcare Surrogate Designation). We are in an era of strict privacy enforcement since HIPAA (The Health Insurance Portability and Accountability Act) became law in 1996.