Coat of Arms of Kate Middleton (prior to her marriage to Prince William the Duke of Cambridge on the 29 April 2011); the arms are derived from those granted to her father (Michael), borne on a lozenge as an unmarried woman.Blazon: 
On a lozenge, "Per pale Azure and Gules a Chevron Or cotised Argent between three Acorns slipped and leaved Or"
Own work, Created from blazon provided by: The Official Royal Wedding Website
Sodacan