Combine sweetened condensed milk and lime juice in a bowl; stir in 1/2 cup Cool Whip.
Press one lime slice into the inside of each popsicle mold about halfway down. This is optional and is just for garnish.
Spoon mixture into nine popsicle molds. The mixture will be a little thick so tap the molds on the counter slightly to remove any air pockets.
Spoon about one tablespoon remaining whipped cream on top of lime mixture and top with about one teaspoon graham cracker crumbs, pressing crumbs gently into the whipped cream mixture so they won’t fall off when unmolded. Press popsicle sticks down the middle of the mixture.
Freeze at least 3 hours or until completely frozen.
Lower popsicle molds down into a large bowl of very warm but not hot water for about 30 seconds. Gently rock the popsicle sticks back and forth while pulling up to remove the popsicles from the molds. Enjoy immediately! Don't forget to remove the lime slice before eating.