Is this Alzheimer's or normal memory loss?

A fellow caregiver asked...

My mother has been experiencing memory loss problems for several years. We have noticed that it's getting much worse. She repeats herself constantly, telling the same story over and over or will ask the same question over and over in just a few minutes time. She has trouble remembering dates/times unless she writes them on her calendar and even then will show up at the wrong time. We have tried to get her to agree to testing, but she tells us that her doctor thinks she is fine. She won't let any of us go to her appointments with her. She is still able to do most everything to take care of herself - cook ,drive, etc. We just want to know if she has this disease so she can get on some medication to slow it down. She is convinced that we are trying to put her in a nursing home (which is what we are trying to avoid!) She has also become less social - no longer attends her knitting group, game group or lunch with friends. When I ask her why, she says "those people drive me crazy". Her mother had Alzheimer's and we don't know if it is genetic. Do you think this is "normal" aging memory loss? Alzheimer's? Dementia? Thank you for your time.