My Mom Is 91 And Had A Stroke 2 Years

my Mom is 91 and had a stroke 2 years ago. SHe had speech therapy and speaks well, no slur, but every now and then her words get jumbled, but i know what she is saying based on our conversation. She sometimes cant say our names, but she recognizes voice, even over the phone, so I don't believe she has Alzheimer. Can't that be just from the stroke, not Alzheimer. She has not been to a Psychiatrist for testing. SHe cooks and cleans, washing clothes, cleans the house, reads her bible, and anything she wants to do except drive. Does this sound like an Alzheimer patient. Can Alzheimer come and go?