I was one of the posters on that thread and have to say I see your point here, Chris. I was a little surprised how isolated my opinion was on that thread. But I think some of the differences pointed to the more general topic of portrait artists' use of photographs, and some of the hazards we need to be aware of if we work from them (of course your book beautifully points out these issues).
It must be my INFP (introverted, intuitive, feeling, perceiving) nature to pick up on the character nuances in a photograph.
I look at this photograph and I get the narrative without knowing the children.
Rebecca, I think this is going to be a great challenge and a lot of fun. What size are you going to work on? Please keep us posted on the progress. I have never seen colored pencil work larger than 16" x 20" and I'm sure there are many quiet forum visitors who are just as curious.