Make the filling: In a cold medium bowl, whip the cream until stiff peaks form. In another bowl, stir together the condensed milk and frozen lemonade. Gently fold the lemonade mixture into the whipped cream. Pour the filling into the crust; freeze overnight.
About an hour before you serve the pie, make the topping: Toss the berries in a medium bowl with the sugar and lemon juice. Set aside until ready to serve.
Let the pie come to room temperature for 10 minutes before cutting. Top each slice with berries.