Strawberry-Mango Lemonade

I had something like this at the Olive Garden recently and had to try and replicate it-it's so delicious and very refreshing on a hot,  summer day.  My kids love it!  I've been making extra mango and strawberry puree and freezing it in small food containers for future use.  You can also freeze the fruit mixture in ice cube trays for a single drink anytime you want it!  :)

4 quarts cold water
2 cups lemon juice concentrate (I use ReaLemon)
1-1/2 to 2 cups sugar
1 ripe mango, peeled and chopped
1/2 to 1 pound ripe strawberries, rinsed and hulled
Sprite or another lemon-lime soft drink, chilled
ice

Make the lemonade:  In a gallon pitcher, combine lemon juice concentrate, sugar and water.  Mix well until sugar is completely dissolved.  Process the mango and strawberries in a food processor or blender until thoroughly pureed.  Add fruit to lemonade and whisk well.  To serve, fill a glass half-full with Sprite and ice cubes, add lemonade and give it a stir.  Garnish with fresh strawberries, if desired.