Combine the meringue powder with water according to the directions on package and beat until stiff peaks. Fold the meringue into the sweetened condensed milk and set aside. Drain the peaches. Reserve the liquid. Moisten the granola with apple juice, adding more as needed to create a moist crumble. Moisten the graham crackers crumbs with apple juice, using the reserved peach juice if you run out of apple juice. Layer the granola mixture into the bottom of a serving dish. Cover with 1/3 of the meringue mixture and 1/2 of the peaches. Top with the graham cracker mixture, 1/3 of the meringue, the remaining peaches and the last of the meringue. Let the trifle sit for 15 to 30 minutes before serving.
For an "elegant" shelter-in-place dining experience, layer the trifle in a wine glass; otherwise, a red plastic cup will do.