On June 12, 2013, Doris Alexander was admitted to PruitHealth-Forsyth nursing home. Her daughter, Carol Alexander, signed a nursing home admission agreement and other documents, including an optional arbitration agreement naming her mother and the nursing home as parties. Doris remained a resident of the nursing home until she died on February 27, 2014. On May 5, 2015, Jeanette Alexander, another of Doris's children, filed suit against United Health Services of Georgia for claims of negligence, wrongful death, and malpractice. United Health filed a motion to dismiss and compel arbitration. The trial court held that there was no valid arbitration agreement because Doris had not signed the agreement and Carol did not have a power of attorney. United Health appealed. Did Carol have authority to sign for her mother?