Thomas Markle "must feel extremely let down" following the break-up of his family, a royal commentator has claimed.Hugo Vickers released his latest book, Queen Elizabeth II, on April 9, 2026, where he explored the relationships between the late monarch and her wider family.In the book, the royal author discussed the Duchess of Sussex's father, Thomas Markle, and the fiasco surrounding her wedding and whether or not he would be in attendance.Both…