Line a large baking sheet with wax paper.
Place sweetened condensed milk and vanilla yogurt in a large bowl, and whisk until blended.
Spoon the mixture on to the prepared baking sheet and spread out in an even layer.
Spoon the strawberry preserves in 1-2 tablespoon dollops over the yogurt mixture.
Using a toothpick, swirl the preserves into the yogurt mixture, creating a marbled pattern.
Top the yogurt with the sliced strawberries and kiwis and place in the freezer, uncovered, for 2-4 hours, or until frozen and firm.
To serve, cut or break the frozen yogurt bark into portions, return any unused portions to the freezer.
Once frozen, feel free to portion into individual servings, and place in a zipper baggie or a sealable container for easy snacking later.