Sprinkle gelatin over cold water in mixing bowl; set aside for 10 minutes to soften.
Add boiling water and stir until gelatin is completely dissolved, and add sugar replacement, lemon juice and rind.
Stir to thoroughly blend.
Cool until mixture is consistency of unbeaten egg whites.
With an electric beater, whip lemon mixture until frothy.
Fold beaten egg whites into lemon mixture.
Spoon into 6 serving dishes; refrigerate until set.