Place 1 peach half, cut side up, on each crust quarter. Spoon sugar mixture evenly onto peach halves. Brush crust edges with beaten egg white. Bring sides of each crust quarter up over peach; press edges to seal, making 3 seams. Place dumplings, seam sides up, in pan. Brush crusts with egg white; sprinkle with 2 teaspoons sugar. Make small slits in top of each dumpling to allow steam to escape.