She's accessorised with a decorative hat by Stephen Jones, a chic clutch and pale heels.
The family the made the short trip back to Buckingham Palace for a military ceremony followed by a flypast, which the royals viewed from the balcony of the palace.
Attending the service included: Prince Charles, The Duchess of Cornwall, Prince Edward, Sophie, Countess of Wessex, Prince Andrew, The Princess Royal, Princess Anne and her husband Vice Admiral Sir Tim Laurence.
Even now with her royal title, there's no doubt the Duchess will continue down this path and bring attention to causes she cares about including, women's health, gender equality, and female empowerment.
Meghan Markle and Prince Harry depart the christening of Prince Louis at the Chapel Royal at St. James's Palace. The 70-year-old wife of Prince Charles stunned as she headed in to Westminster Abbey in a white cocktail-style dress which boasted 3/4 length sleeves and voluminous applique pockets.
The group walked into the Abbey altogether and spoke with the Archbishop of Canterbury, who just a day earlier had Christened Prince Louis.More news: Tab Hunter Dies at 86
The RAF, which is the first-ever independent air force, split from the British Army and Royal Navy in April 1918. William was the fourth successive generation of the monarchy to become an RAF pilot.
The Duke and Duchess of Sussex attended the service before they jet off to Ireland for their first official foreign tour since their wedding.
Prince William and Catherine have chosen three godmothers and three godfathers who are all close friends and family members, not including Prince Harry and Meghan, to be little Louis' godparents.