Combine pudding mix and milk in a bowl. Beat with a hand mixer for 2 minutes, or until soft set.
Crumble one shortbread cookie into the bottom of one jar. Top with 1/4 cup pudding, some sliced peaches and some blueberries.
Repeat layering with a second crumbled cookie, 2 tbsp pudding and more fruit. Top with 2 tbsp pudding and garnish with more fruit. Repeat with 3 remaining jars. Refrigerate until serving.