Princess Margaret's Coat-of-Arms -- Princess Margaret's Coat-of-Arms. The Royal Arms and Supporters difference by a label of three points Argent, the centre point charged with a Thistle slipped and leaved proper and each of the other points with a Tudor Rose and ensigned with a Coronet comprised of Crosses and fleur de Lys. Princess Margaret will be 18 on Saturday, August 21st. The Princess has her own Coat-of-Arms and the King has approved the design for her personal Standard. Both were prepared by the College of Arms. August 18, 1948. (Photo by Reuterphoto).