Even though Kate Middleton and Prince William‘s three kids — Prince George, 6, Princess Charlotte, 5, and Prince Louis, 2 — have more luxuries than most children their age, the trio are nowhere close to being spoiled.

“Their parents are teaching them to be well-mannered and respectful,” an insider exclusively tells Closer Weekly in the magazine’s latest issue, on newsstands now. “The children always have to say ‘please’ and ‘thank you.'” Not only that, but Kate, 38, and William, 37, don’t ask their “housekeeper” to help their kids out with their chores.

Princess Charlotte Looks Precious While Lending a Helping Hand
Courtesy The Duchess of Cambridge via Kensington Palace Instagram

“George and Charlotte make their own beds in the morning,” the insider explains. “Kate can’t believe how quickly her children are growing up. Sometimes she’ll joke that she wants them to stay little forever, but she also loves seeing them reach new milestones.”

On Saturday, May 2, the parents of three celebrated Princess Charlotte’s 5th birthday. As she gets older, her parents have noticed the princess is becoming more of “a headstrong little girl,” but also someone who’s “adorable and kindhearted.” However, she does get into her fair share of trouble with Prince Louis, like the time Charlotte helped her baby bro find Kate’s secret stash of sweets.

“Kate’s found Louis covered in chocolate,” the source hilariously explains. “When the two of them disappear off together, she assumes they’re up to no good — but in an endearing way.”

George, on the other hand, has been busy taking pictures with the new camera he got for Christmas. “He’s an inquisitive child and a methodical thinker who thrives on figuring things out,” the source reveals. “If George could spend all day building, doing puzzles and putting things together, he would.”

When George is not playing with siblings, he’s at home takes classes remotely with Princess Charlotte. The Duke and Duchess of Cambridge “admit that homeschooling and having to entertain the kids all day has been a bit of a nightmare. Kate and William are worn out by 7 p.m.!” the source reveals. “But they feel very fortunate to have such sweet, well-behaved kids.”

For more on the royal family, pick up the latest issue of Closer Weekly, on newsstands now — and be sure to sign up for our newsletter for more exclusive news!