Izabella Niedzialek was in full hiking gear. Standing at the base of the Appalachian Trail, hiking stick in hand, the second-grader was grinning from ear to ear when someone asked her about the trail’s history. The trail was just a few feet away from the MARTA station, which led to Turner Field, the Georgia Aquarium and the Blue Ridge Mountains, where second-grader Natalie Armour was stationed as a tour guide.