Prepare the crust: Place the flour, sugar and salt in the bowl of a food processor; pulse the machine on and off to combine. Add the butter and shortening; pulse until the mixture resembles coarse meal. Gradually add the ice water, pulsing the machine on and off, until the dough holds together. Divide the dough in half and form into 2 disks; wrap in plastic and chill in the refrigerator for at least one hour, or overnight.
Butter a 9-inch Pyrex pie plate. Remove one disk of the dough from the refrigerator. Roll it out on a lightly floured surface to form a round, 1/8-inch thick and 2 inches larger than the pie plate. Work quickly so that the dough doesn't become sticky. Using a spatula to help lift the dough, fold it loosely in half and then into quarters. Gently transfer it to the center of the pie plate. Open up the dough and press it lightly in the plate to fit. If the dough should tear, just press it lightly together. Trim the dough, leaving a 1-inch overhang. Place in the refrigerator to keep cold.
Line a baking sheet with waxed paper. Remove the other disk of dough from the refrigerator and roll it out the same way; transfer to the baking sheet and cover with another sheet of waxed paper. Place in the refrigerator to keep cold.
Position a rack in the center of the oven and preheat the oven to 425°F.
Prepare the filling. Using a paring knife, cut an "X" in the bottom of each peach. Drop the peaches into a pot of boiling water for 1 minute. Remove to a bowl. When they are cool enough to handle, slip off the skins. Cut the peaches into 3/4-inch slices and place in a large bowl. Toss with the lemon juice to prevent discoloring.
Add the blueberries, vanilla, brown sugar, 1/2 cup granulated sugar and the flour; toss well.
Lightly brush the bottom crust all over with the egg white; spoon in the filling and dot with the butter.
Cut the top crust into strips 3/4-inch wide and make a lattice cover over the filling. Trim the overhang to 1 inch.
Moisten the edges of the crusts where they meet with a little water, then press them together lightly and turn them under. Crimp the edges decoratively.
Brush the lattice crust and the rim with the cream. Sprinkle the surface with the remaining 2 tablespoons of sugar.
Place the pie on a baking sheet and bake in the oven for 15 minutes. Reduce the heat to 375°F and bake until it is golden and the juices are bubbling, about 50 to 60 minutes. If the top is getting too brown, tent the pie with foil after about 30 minutes.
Let the pie cool on a wire rack before serving.