Princess Eugenie stepped out with Prince Harry’s ex-girlfriend, which was her first sighting since the King’s cancer diagnosis was announced. The Princess of York’s mother, Sarah Ferguson, and her uncle, King Charles, have both recently been diagnosed with cancer. But Eugenie, 33, appeared in good spirits as she joined her close friend Cressida Bonas for a pub trip on Thursday. Princess Eugenie was the person who introduced her cousin Prince Harry to Bonas, and they dated between 2012 and 2014. The princess and the actress have remained close despite the break-up. Eugenie donned a Sandro tarta…