First, I love that she writes visually! Our #2 (also visual spatial, not ADHD) does something similar, to a less extravagant extent.
Secondly, yes, high PRI usually means visual spatial kid. Both high matrix reasoning and ADHD are associated with creativity/divergent thinking.
At some point, she will probably have to learn how to evoke the visual, spatial, and sensory images she currently portrays concretely using words to generate the experience in the reader's head. I would not be surprised if she becomes an effective writer, retaining some of her unique energy, as she learns more sophisticated perspective-taking. (Creating the wackiness internally for the reader, rather than externally.)
Graphic organizers are also likely to play a big role in her written expression development, as a transition/stepping stone to words that teachers can appreciate.
