LONDON — The royal family paid tribute Saturday to the British man killed in the New Orleans truck-ramming attack, a 31-year-old who was the stepson of Prince William and Prince Harry’s former nanny.

Edward Pettifer was among 14 people killed when an ISIS-inspired U.S. Army veteran drove his truck into a crowd of revelers on New Year’s Day, his family confirmed Saturday.

“The entire family are devastated at the tragic news of Ed’s death in New Orleans. He was a wonderful son,…