Finally, the dress It was the best-kept secret of the wedding and it threatens to steal the show. Finally, the dress 29-year-old Kate Middleton is in a full-sleeved Chantilly lace dress with a strapless slip underneath. Finally, the dress It is full-sleeved. Commentators praised it as ?Grace Kelly-esque.? The dress has a shorter train than expected. Finally, the dress The designer who created the dress is Sarah Burton by Alexander McQueen. Finally, the dress Kate wore her hair partly up, with a stunning tiara made in 1936. Her hair was softly curled at the end.