Place kiwifruit and sugar in blender; cover and blend on medium just until smooth. Pour into another container; freeze 1 to 2 hours or until firm.
Place watermelon in blender; cover and blend on medium until smooth. Place frozen lemonade concentrate and water in large pitcher. Add watermelon mixture; mix well.
Pour watermelon lemonade into glasses. Spoon a dollop of frozen kiwifruit mixture on top. Serve immediately.