'In Awe of What She Does': James Middleton Says Sister Kate Is the 'Same Person I Grew Up With'

James Middleton, 37, gave a "rare" interview where the author of Meet Ella: The Dog Who Saved My Life showered praise on his elder sister, Kate, Princess of Wales, 42, who recently beat cancer.

"Catherine is very much on a public stage, and I’m in awe of a lot of the things she does," James told Us Weekly. "I think the thing I'm most proud of is that she's still the same person that I grew up with."

The Princess of Wales will one day be the author's Queen, and James and Pippa Middleton couldn't help but show their excitement about that possibility when Kate told them Prince William proposed in late 2010.

"Pippa and I want to be visibly excited, but we have to tamp down our emotions so no one suspects a thing," he wrote in his new book. "We make a quiet acknowledgment that we’ll always be there for each other, look out for one another, support each other. No matter how crazy things get."

The entrepreneur's struggles with mental health have been well-documented over the years, with contemplation to end his own life in 2017 triggering Kate to assist her sibling during his darkest days.

"Catherine had been doing a lot of work with Heads Together, so there was actually more awareness of how to communicate," he told the outlet, while also highlighting Kate and William's mental health initiative.

James also revealed the future queen's well-known "earthiness," which is also something that appealed to the late Queen Elizabeth II, according to a royal insider.

HRH was "down-to-earth and unpretentious," he said when referencing Kate's job at clothing store Jigsaw in 2006. "She sat in the kitchen at lunchtime and chatted with everyone from the van drivers to the accounts girls. She wasn’t precious."

Author Robert Jobson, whose new book Catherine: the Princess of Wales: The Biography detailed the art history graduate's love of creativity, wrote, "When in London, she [Kate] has been known to head out early in the morning to fulfill that passion with secret visits to art galleries. It is a rare occurrence, and she has confided that she really misses getting the fix from that cultural side of her life."

Catherine's inner sanctum outside of Prince William and her three children has only contained her immediate family members and "less than a handful of friends, for years.

"The circle of trust is tiny," a friend of the Prince and Princess of Wales spilled. "She has been surrounded by Carole and Michael, and Pippa and James have obviously been there for her as well."

After six months of chemotherapy treatment, Her Royal Highness is believed to have kicked a still-unknown type of cancer in early September.