Dissolve gelatin in boiling water.
Add lemon-lime beverage, stirring well.
Pour 1 cup gelatin into a lightly oiled 8-inch square dish.
Chill until set but not firm.
Prepare whipped topping mix according to package directions; set aside.
Add peaches and cocktail mix to remaining gelatin, stirring well; fold in whipped topping.
Pour mixture over first layer.
Chill until firm.
Cut into squares to serve.