5 Things to Know About James Middleton’s Fiancee Alizee Thevenet By Miranda Siwak of US Weekly | It’s Alizee Thevenet, the pair are still just as in love with each other as the day she said “oui.” Duchess Kate’s younger brother, 34, dedicated an Instagram post to his future bride, 31, in September 2020 after getting down on one knee one year prior. He wrote, “It’s a year since I asked Alizee to marry me … what a year it’s been! Two homes lockdown … and much more but the best part is that I get to share it with you @alizeethevenet and I can’t wait to take on whatever the future holds for us .”