11-year-old Nicky, Ricky, Dicky, and Dawn Harper's sibling rivalry are heightened by the fact that they are quadruplets.11-year-old Nicky, Ricky, Dicky, and Dawn Harper's sibling rivalry are heightened by the fact that they are quadruplets.11-year-old Nicky, Ricky, Dicky, and Dawn Harper's sibling rivalry are heightened by the fact that they are quadruplets.