By Emily Mitchell/Reported by Wendy Cole

Big sister has given her approval. Princess Diana was as surprised as anyone else when her younger brother Charles, Viscount Althorp, 25, abandoned his Champagne Charlie image and proposed -- in time-honored manner -- on bended knee. But she was delighted with model Victoria Lockwood, 24, whom she met during the couple's six-week courtship. Charles, a reporter on NBC's Today show, says it was love at first glance. "We are both dead certain," he proclaimed. Plans for an autumn marriage are perking up royal watchers, who have gone for nearly a year without a wedding or a baby.