No. Trying to use reason or logic with a person with Alzheimer's or any form of dementia will only escalate the situation and is often an antecedent to violent behavior. It can be very frustrating trying to get anywhere when working with those who have any form of dementia, but please remember, she is sick. Her brain is literally damaged, and her reality does not match yours. It is not her fault. Often times with Alzheimer's, the most caring thing to do with them is to "enter their world", sometimes called "reality therapy". In other words, just play along. As long as your doing so is not hurting anybody, it can be beneficial to her as it will allow her to have some temporary peace. When interacting with a person with Alzheimer's, one must give up the need to be right. Please explain to whomever it is that she is giving a hard time, that she has a medical condition that alters her perception of reality and she is not lucid for much of the time. Explain that her behavior is not a reflection on that person. In the event that you need her cooperation for something crucial like a doctor's appointment, I totally agree with M'aiq the Liar-- lie if it is the only thing that works. Sometimes the kindest and least harmful thing you can do given the situation is lie, especially if doing so allows her the medical care she is needing.
I was trained in and have extensive experience with Non-Violent Crisis Intervention as a part of my career as an Abuse/Neglect and Human Rights violations investigator for at-risk adults. I also used to care for an adult with advanced Alzheimer's disease.