Which one a neurologist or geriatric psychiatrist for someone diagnosed with alzheimers?

My sister-in-law, whom we have guardianship of, currently goes to a geriatric psychiatrist. While we are not unhappy with him, we would like to find a doctor closer to us. She has been diagnosed with Alzheimer's and we don't dispute that. Many patients go to a neurologist and am wondering if we should find one for her.