Carole Middleton played a pivotal role after Princess Kate’s heartbreak, a royal commentator has claimed. Before tying the knot in 2011, Prince William and Kate briefly split up in 2007 before rekindling their romance. Royal commentator Robert Jobson has detailed the Prince and Princess of Wales’s dating history in his new biography, Catherine, Princess of Wales. He wrote: “As Catherine approached her 25th birthday in January 2007, [William] unexpectedly cancelled plans to attend a New Year gathering in Dundee, arranged by the Middletons. “She sensed something was wrong. It certainly wasn’t he…