Little saints PHOTOS BY MIGUEL JUAREZ staff Top photo, Isaac Mercado, a kindergartner at St. Ambrose School, Old Bridge, and his mother place crayons in a backpack that will go to a child affected by Hurricane Katrina. Above, fourth-graders Lexa Granat and Erin Schneider fill backpacks with school supplies Monday. Below, kindergartner Liam Hack and his mother, Marie, participate in the effort.