Heat oven to 300°F. Lightly grease 13x9-inch pan. In large bowl, combine egg whites and cream of tartar; beat at high speed until frothy. Gradually beat in 1 cup sugar until stiff peaks form. Add vanilla; beat well. Spread mixture in greased pan.
Bake at 300°F. for 40 to 45 minutes or until meringue is light golden brown and appears dry. Cool 30 minutes or until completely cooled.
In large bowl, combine cream cheese and 1/2 cup sugar; beat until well blended. In medium bowl, beat whipping cream until stiff peaks form. Fold whipped cream and marshmallows into cream cheese mixture.
Spoon lemon pie filling over meringue; spread evenly. Top with cream cheese mixture, spreading evenly. Cover; refrigerate at least 8 hours.
In medium bowl, combine cherry pie filling and strawberries. To serve, cut dessert into squares; place on individual dessert plates. Spoon cherry-strawberry mixture over each serving. Store in refrigerator.