Set 1 c vanilla yogurt aside. Add 1 c hulled strawberries to high powered blender. Blend until smooth. Add lemon juice to taste (I added 1 tsp). Pour into bowl, set aside. Rinse blender out.
Add 1 c blueberries to blender, blend until smooth. Add lemon juice to taste (I added about 1 tsp). Pour into bowl and set aside.
Layer in blueberry puree, then yogurt, then strawberry puree into each mold. Fill until almost the top.
Place popsicle sticks in each mold and swirl ingredients to get some marbling if desired.
Place mold in the freezer for at least 5 hours.
Remove mold from freezer immediately before serving. Run mold under warm water to release popsicles. Enjoy immediately.