Prince George and Princess Charlotte's Relationship Models 'Heir and the Spare' Ideal

Katie Nicholl, author of 'The New Royals,' explains Prince George and Princess Charlotte's 'heir and the spare' relationship. The dynamic between the kids of Prince William and Kate Middleton follows a tradition of sort for the family; the late Queen Elizabeth II had it with her sister, Princess Margaret; King Charles III had it with his sister, Princess Anne; and then there's William's relationship with younger brother Prince Harry.