In a blender, place the strawberries, banana, and frozen lemonade. Fill the empty lemonade can halfway with rum, if using, and add it to the blender with the sugar and ice. Blend until well combined and slushy. Add the orange juice to thin the mixture if necessary, or more ice cubes to make it thicker.
Divide among 2 or 3 glasses. Garnish with a fresh strawberry and serve.