Queen Elizabeth wasn't the only relative whose approval Prince Harry sought before popping the question to Meghan Markle in 2017. The Queen's official consent is required for any royal before they're allowed to wed, however, it's reported that Harry really wanted his sister-in-law Kate Middleton's approval of his then girlfriend. Royal expert Katie Nicholl wrote in Grazia UK that Harry made sure to introduce Meghan to Kate during the early days of their courtship.
According to Nicholl, "Harry and Kate are very close, she’s been like a mentor to him and he wanted her seal of approval." The Duchess of Cambridge met Prince Harry's older brother, Prince William, while they were in college and they date for many years before finally saying "I Do" at Westminster Abbey in 2011. Harry has known Kate since his late-teens / early-twenties, so, it makes since that they've developed such a strong bond.
Newsweek reported that "When [Kate] and William got engaged, Harry called her the big sister he never had. He often pops into their apartment at Kensington Palace, where she cooks him a meal—roast chicken is reportedly a particular favorite."
Kate and Meghan first met way back in November 2016, only four months after Harry and Meghan's whirlwind romance began. The duchesses reportedly hit off right away and reunited again in January in 2017. Meghan was back for another visit with Harry and made sure to bring along a gift for Kate's birthday.
Since joining the Royal Family back in May, Meghan has grown closer to her sister-in-law. "Kate is different to Meghan in many ways, but she has made great strides to help Meghan settle in," Nicholls reported. Kate has reportedly "gone out of her way to make Meghan feel at home at Kensington Palace. Especially with Meghan being on foreign soil with few friends and no family in the UK, and, of course, the recent difficulties she has been through with her father, who last week spoke about her to the press once again."
It must mean a lot to Prince Harry to see the two of the most important women in his life grow so close over the past two years. They really do seem like one, big, happy, (royal) family.