I have a feeling that, unless you are blind due to illness of the brain, that everyone has the capability to visualize internally. This would include your wife when she is reading. I think they difference is that some people have access to this visualization consciously, with their frontal cortex, and for others it's subconscious. If you didn't have this visualization, I believe it would be really hard to commit what you read to memory and have any sense of a story.

When I meditate, one of the practices is to label thoughts as they arise. When you do this, you realize that a huge amount of thoughts pass by subconsciously. You notice them more and more as you label them, but it feels like a deep rabbit hole of thought that I haven't gotten to the bottom of yet.

edit: just looked at the article and realized that the technique is essentially thought labeling. This is one of the most common practices in Buddhist meditation.