An enduring guardian is someone you choose to make lifestyle and welfare decisions for you when you are not capable of doing this for yourself.
You choose which decisions (functions) you want your enduring guardian to make (have) and you can give your guardian directions on how to carry out those functions.
An enduring power of attorney permits an attorney to make decisions about all of your money and property if you are not capable of doing this for yourself. A power of attorney does not permit an attorney to make lifestyle and welfare decisions for you.
Usually lifestyle decisions are made by your immediate family. However, a decision made by a family member who is not your spouse or defacto spouse may not have legal force if it is not something that is specifically permitted by part 5 of the Guardianship Act (which deals only with certain medical and dental procedures – life style decisions include so much more than that).
In certain circumstances, the Guardianship Act permits for someone other than your immediate family, who has had your care (other than for payment), to make application to be the person who can make decisions about certain medical and dental procedures (referred to as the “person responsible”). That may not be what you want.