Princess Anne, who has taken Princess Charlotte under her wing, is teaching the ropes of royal life to Prince William and Kate Middleton’s daughter.

The Princess Royal, who is dubbed as the hardest working member of the royal family, has warned her against the "worst faux pas" that occurred, which was by her uncle Princess Harry, per a palace insider.

Anne is “inadvertently” giving Charlotte some “juicy gossip” including the tale about Prince Harry “partying in a Nazi uniform and to Princess Beatrice’s dreadful fascinator at her parents' wedding.”

“They're talking ALL the time about everything and anything, women’s football, sailing, horses, ballet, fashion, manners,” the insider told Woman's Days Magazine. “Essentially, she's fool proofing Charlotte into becoming the perfect princess and standby queen.”

Apart from the lighter elements of Charlotte’s “Princess training,” Anne is understood to be “rigorous.”

Meanwhile, William and Kate are “thrilled” about Anne passing down the wisdom to their daughter. The insider said that the couple “couldn't imagine a better role model than Anne, who is renowned for her work ethic and impregnable support for the King.”

And the Princess of Wales is hoping that Charlotte also receives the same “candid tough love” when she officially joined the royal family.