1) For the estate, there must be a will naming you as executor and providing instructions or directions as to who inherits what (it can all go to you, if that's what the will says).2) For medical decisions, you need a health care proxy or living will naming you to make medical decisions for her (the name of this document varies by states).Any trusts and estates attorney can very easily draw up these documents for your friend and make sure they are properly signed and witnessed. (If not signed and witnessed the right way, they will not have any power.) Or your friend can create these herself: she should be able to find sample forms and instructions online, but needs to also look up and review (and be confident in her ability to review) your state's laws about these documents, to make sure that she includes any necessary language and has them properly signed and witnessed.