What do we have to do for me to be able to make decisions while I am there, serving as the "alternate" POA?
The primary place to go to for guidance as to your authority as an alternate agent under the Durable Power of Attorney is the document itself. The authority of an alternate agent can vary tremendously from document to document. Your father's particular Durable Power of Attorney will indicate under what circumstances you can act in place of your sister. It is difficult to give precise information to you without seeing the actual Durable Power of Attorney, but often there would be a provision empowering you to be able to act if your sister is unwilling or unable to act. In that case you would need written certification of that fact. In any event, your best course of action would be to contact the lawyer who drafted the Durable Power of Attorney for assistance in creating the proper documentation to authorize your acting through the Durable Power of Attorney.
