Gently stir peaches, blueberries, and lemon juice together in an 8-inch square baking dish. Stir 2 tablespoons flour and white sugar into the fruit mixture.
Stir oats, brown sugar, 1/4 cup flour, almonds, cinnamon, and nutmeg together in a small bowl. Mash butter into the oats mixture with a pastry cutter or a fork until the mixture is crumbly; sprinkle over the fruit to cover.
Bake in preheated oven until the fruit is bubbling and the topping is golden brown, about 30 minutes.
