In a bowl, whisk together sweetened condensed milk, lemon juice, lemon peel, and yogurt. Stir in marshmallows and pecans.
Spread half of the mixture in an ungreased 8 x 8-inch square dish. Sprinkle with half of the strawberries and blueberries. Cover with the remaining yogurt mixture; top with remaining berries.
Cover and freeze. Remove from freezer 15 to 20 minutes before serving.
Recipe by Not Just Sunday Dinner at https://notjustsundaydinner.com/patriotic-frozen-delight/