I am preparing (with a colleague) a non-fiction book for publication. We are completely inexperienced authors.
The book is about a group of children and their lives in a care environment.  Half of the book comprises the former children’s narratives - created from transcribed interviews.
We have had a volunteer editor (an experienced academic) convert the interviews into coherent narratives - an amazing job!  We would like to offer them the opportunity to write a segment in the book’s front matter - but it will not be a foreword (We have someone specific in mind to write the foreword, who has intimate knowledge of our research and journey through the  process).
So what can we call the frot matter contribution from our “narratives editor”?
I have not found any guidance online for this situation.