Prepare instant lemon pudding according to package directions, using the milk. In a medium-sized bowl, with an electric mixer at medium-high speed, beat cream until soft peaks form. Fold whipped cream into prepared lemon pudding. In 4 or 6 individual serving glasses or a 1-quart bowl, spoon a layer of the pudding mixture; sprinkle lightly with cookies and a layer of blueberries. Repeat layers one more time, ending with the pudding. Refrigerate, covered, for about 30 minutes. Garnish with mint sprigs and blueberries, if desired.