1Combine apple and 2 tablespoons lemon juice in a large bowl; toss gently. Add celery, grapes, walnuts, and raisins; toss gently to combine. Set aside.
2Combine salad dressing, sugar and 1 teaspoon lemon juice in a medium bowl; stir well. Set aside.
3Beat whipping cream at high speed of an electric mixer until soft peaks form. Gently fold whipped cream into reserved salad dressing mixture. Add whipped cream mixture to reserved apple mixture, stirring gently to combine. Stir in flaked coconut and marshmallows. Cover salad, and chill thoroughly.