The 34-year-old Duchess of Cambridge discussed her relationship with the 89-year-old English monarch in Our Queen at Ninety, an ITV documentary celebrating Queen Elizabeth's 90th birthday.
"She's been so generous and not sort of being forceful at all in her views," Middleton said of husband Prince William's grandmother. "I feel she's been a gentle guidance really for me."
"[My son, Prince] George, is only two-and-a-half. He calls her 'gan-gan,'" the duchess revealed. "She always leaves a little gift or something [for Prince George and Princess Charlotte] in their room when we go and stay, and that just shows her love for her family."
Middleton and Prince William married in 2011 and welcomed George and Charlotte in 2013 and 2015, respectively. The duchess also revealed she gave Queen Elizabeth homemade chutney for Christmas during her first holiday as a newlywed.
"I was worried what to give the queen as her Christmas present," she recalled. "I thought back to what would I give my own grandparents and thought, 'I'll make her something,' which could have gone horribly wrong. I decided to make my granny's recipe of chutney."
"I was slightly worried about it, but I noticed the next day that it was on the table," she said. " I think such a simple gesture went a long way for me and I've noticed since she's done that on lots of occasions. I think it just shows her thoughtfulness, really."
Our Queen at Ninety will air March 27 on ITV. Queen Elizabeth, who will celebrate her 90th birthday April 21, was spotted at dinner with daughter Princess Anne and cousin Princess Alexandra at Bellamy's on Monday.