All I can surmise from this is she was remembering the times when she used to babysit him as a young boy, and how she used to make him this soup that he really liked, and perhaps longing for that feeling.
It's really interesting for me to observe what she remembers and what she doesn't. What's even more interesting is HOW she remembers certain events or conversations. I think my mom chooses to remember events the way she would like to. Perhaps she remembers in a way that makes her feel good, or the way she would have responded or reacted - an "emotional memory" if you will. I don't even know if her creativity is due to medications she is taking for her Alzheimer's: Namenda and Aricept.
According to a recent Discover article "Past Imperfect", scientists previously thought long-term memory was etched into our brains, permanent and unchanging. Recently however they are discovering that long-term memory is much more dynamic and can be rewired. In experimental treatment, patients with PTSD (post-traumatic stress disorder) were able to permanently change the way they remembered a traumatic incident.
So, is my mom's creative storytelling due to Alzheimer's, or is she just rewriting the stories of her life based on how she wants to remember them?