Meghan Markle made her royal debut at the Wimbledon tennis championships on Saturday, when she joined her sister-in-law Kate Middleton to watch the men's semi finals, followed by the women's finals. The Duchess of Sussex had a good reason beyond her royal duties for choosing this particular match: her close friend Serena Williams was playing! To support her friend, Meghan chose a classic preppy look consisting of a blue and white striped button-down, and chic white pants by Ralph Lauren.