As with other fans of this series, I noticed at the back of each issue one or two pages would be devoted to 'ads' showing missing children with information on who to contact if you ever saw them. This was something Teri decided early on to put into her comics. In issue #17's letter column Teri put it this way. "Basically, it just boiled down to that it seemed like a good thing to do."
OK, not a lot of detail, but it's better than putting ads back there for the next hot movie or somthing.
Well, after some research (ie: web surfing) I found this site with an interview with Teri from a few years ago. In it she gives more details...
Jeff: I noticed that on the back cover of each issue of Wandering Star
you have pictures of missing children, like we see on milk cartons,
why is that?
Teri: You know you're the first person to ever ask that! [laugh]
Well, I made the decision on Christmas 1992. We weren't really
celebrating that year. My father had passed away during the
Christmas season the year before, and Mom and I were sitting in the
living room being depressed and watching T.V., and somehow we
found ourselves watching this show on missing children. As we sat
there watching all these faces of children rolling by, I thought how
much my father would have wanted to get involved in this. He was
always getting involved in things that helped children, Little League,
that sort of thing. I said something along these lines to Mom, and she
said, why don't you use your back cover of Wandering Star to show
these kids? So that's how it all began. It's kind of a tribute to my
father.
Jeff: Do you plan to do that through the rest of the series?
Teri: Through Wandering Star, through Dark Light, through every
book I ever do.