Kate Middleton, the Duchess of Cambridge, has been praised for her significant role in the royal family, particularly in shaping Prince William's future as the next monarch. Sally Bedell Smith, an American journalist and biographer, has credited Kate for making a "big difference" in Prince William's acceptance of his future responsibilities.

Smith asserts that Kate has provided "pivotal support" to her husband as he navigates the legacy of King Charles and the late Princess Diana's challenging marriage. The Duchess of Cambridge's influence has helped Prince William become fully committed to his role within the institution.

According to Smith, Kate has demonstrated to Prince William that he can move beyond the difficulties of his parents' relationship. "For a long time, William and Harry were very bonded by having endured that very dysfunctional marriage," Smith told Newsweek. "And William, I think, partly through marrying a woman who would understand that and who would support him, and particularly support him in his role as a future king, I think that made a big difference."

Since their marriage in 2011, Kate has been a significant influence on Prince William, and Smith believes he is fortunate to have her support.

Royal biographer Howard Hodgson also views Kate as an "extremely good influence" on Prince William. "Certainly William is very dutiful, and I think supported by Kate," he told Express. "They ensure that they keep a good appearance. They do put the public, the country, and the monarchy first," he added. "I think he was very lucky to marry her. I think she's an extremely good influence and is well-liked by the people, and so she should be."

Although Kate faced criticism for her work in the royal family during her early years, her focus on building her family with Prince William and supporting him has allowed her to grow in confidence and become more at ease in her current roles.