The Royal Family has issued a rare statement for Lady Louise Windsor. The daughter of the Duke and Duchess of Edinburgh is celebrating her 21st birthday today amid her studies at the University of St Andrews. The young royal does not carry out official duties despite being the niece of King Charles. The Royal Family usually does not issue birthday messages for non-working members of the Firm, which would include Louise. However, they make exceptions for milestone birthdays, which would include Louise’s 21st milestone. They wrote on social media today: “Happy 21st Birthday to Lady Louise!” The …