Stir fruit purées in separate bowls with sugar to taste (about 2 1/2 tbsp. each) and lemon juice to taste (none to 2 tsp. each).
Pour berry layer into 8 juice bar molds, add juice bar sticks, and freeze until firm, about 1 hour. (Chill remaining purées.)
Pour apricot layer over berry layer and freeze. Repeat with plum layer. Freeze until firm, at least 1 more hour.
Briefly dip molds in warm water to loosen.
Note: Nutritional analysis is per fruitsicle.