Preparations are well underway for the Queen's Platinum Jubilee celebrations, with Brits set to enjoy a four-day weekend filled with celebrations.The Royal Family will come together to mark Her Majesty's historic 70-year reign in June, and that includes Prince Harry, 37, and Meghan Markle, 40, who will be heading over to the UK from their home in California for the festivities.The Duke and Duchess of Sussex, who were spotted looking loved-up at a polo match in Santa Barbara recently, are said to be planning to fly over with their two children, Archie, three, and Lilibet, eleven months. The trip will mark the first time that they've travelled to the UK as a family of four, and a source has revealed that the couple are most excited for the Queen, 96, to meet their young children.