Place the strawberries, sour cream, and sugar syrup in a blender and pulse a few times.
If the mixture looks like it's just being chopped rather than blended (as strawberries can vary greatly in their juiciness), add the milk. One everything is blending well, blend until very smooth.
Pour into popsicle molds and freeze until completely firm, at least 4 hours.
Notes
Note about yield: This recipe makes approximately 3 cups of popsicle mixture, which makes 10 popsicles in this simple popsicle mold. Note about sugar syrup: Sugar syrups are simple to make - all you need are sugar and water. See how to make herbal sugar syrup here, and simply skip the step with the herbs.