For the kids: In a food processor, pulse together coconut and breadcrumbs until coconut is in small pieces; transfer to a shallow bowl, and scatter a handful over a baking sheet. Set aside. In another shallow bowl, lightly beat the egg whites.
Toss shrimp with 1 teaspoon salt and 1/4 teaspoon pepper. Working in batches, dip shrimp in egg whites to coat completely; lift from whites (shaking off any excess), and dredge in coconut mixture. Lay on prepared baking sheet.
In a large, deep heavy-bottom pan, heat oil over medium heat until 350 degrees on a deep-fry thermometer. Cook half the shrimp, lightly shaking to separate shrimp, until golden brown, 2 to 4 minutes. Use a slotted spoon to transfer shrimp to paper towels to drain. Return oil to 350 degrees; repeat with remaining shrimp.
Reserve half the shrimp for the adults. Serve remaining shrimp with sweet-and-sour sauce.
For the adults: In a small bowl, whisk together yogurt, lime juice, mustard, and curry powder. Serve the sauce with reserved shrimp; garnish with lime wedges, if desired.