I imagine that a lot of girls who weren't reading comic books in 1963 were reading girls' series books like Nancy Drew and Trixie Belden.  The Trixie Belden series' volumes written in the early 1960s also have the club of teenagers in the book raising money for UNICEF.

Think of it as part of the Camelot era--when the Peace Corps was new, and there was a huge wave of countries in Africa gaining independence from the late 1950s to the mid-1960s , and the idea of helping people there wasn't politically controversial.