Princess Marie-Chantal of Greece on Her New Etiquette Book — and Having Prince George Wear Her Design!

Crown Princess Marie-Chantal of Greece has found a unique way to combine parenthood, her royal status and her own children’s wear company. After blogging about her life, the mother of five has now published a book, Manners Begin at Breakfast, which navigates the dos-and-don’ts of party conversation, etiquette and helping kids be polite and kind.

After growing up in London, Hong Kong and New York, she married Prince Pavlos of Greece in July 1995 and set up her eponymous kids’ clothing line in 2000. It has now expanded into the U.S.

“I’m a mom of five kids between 23 and 11. People had been asking me how I managed with five different children and their schools and I had a business,” she tells PEOPLE. “A lot of it revolved around etiquette, whether it was how to dress a child at christenings, or at Christmas, and how to teach them basic manners, and it started to evolve.”

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She says the time was right to release a book on etiquette.

“In an age when we are slowly forgetting our manners, it’s a nice general reminder why manners matter, especially when we are raising children,” she says. “We sometimes forget to be caring towards others — and that’s where manners fundamentally start. Teaching your children from a young age to appreciate others who are around you, to stand up for an adult and say your please and thank yous.

“On social media people forget how to be kind. It’s easy to be abrupt and to not think emotionally. Teaching kids empathy is more important than ever today.”

Marie-Chantal says that despite her royal status, she’s just like any other modern parent.

“Being married to a Greek and him being a prince, people wanted to see if there was any difference,” she adds. “But as a parent, there are no differences. We are raising children equally. I wanted to be able to bring that reality into fruition, hence the blog and me sharing those stories.”

Mark Cuthbert/Julian Parker/UK Press/Getty Images Crown Prince Pavlos of Greece and Crown Princess Marie-Chantal of Greece

Marie-Chantal grew up in a cosmopolitan, well-traveled family, “but this was still very different,” she says of marrying into royalty. “I entered a very close-knit family. My parents were happily married, my husband’s parents were happily married. I was very lucky to be embraced and not shy to ask any questions about how I was to behave.”

But there was one key request: “I had to ask my mother-in-law and sisters-in-law about who to curtsy to. I’m lucky that I have a very good relationship with my in-laws and they were always very gentle in how they guided me.”

One of her tips will help if you’re at a dinner party in the U.K. — guests are expected to talk to the person on their left first.

“It’s so that everyone is included in the table conversation. I’ve been at dinner parties where there’s no rule of law and you are left sometimes staring at your plate and no-one’s talking to you. I think it was Prince Albert who invented it so that everyone had a chance to speak and no-one would be left out,” she shares.

As for what her kids think about her manners book, she says: “Now they are reminding me that I have a book coming out shortly and I’m not allowed to be on the phone in the morning at breakfast. We all have to remind ourselves every now and again what’s important and what’s not important!”

“This morning I have the two little ones,” she adds. “They were at the breakfast table at 7 a.m. My 19-year-old who’s studying at university but spends a few days at home – and he came down at 11 a.m. because he has class at university at 1. Things do change – but when they were little it was very much the rule that we would all sit together. Today the breakfasts have been replaced by Sunday lunch where family comes together and then the big holidays like Thanksgiving or Christmas. Then it is very much I tell them they have to be down at breakfast at a certain time and they respect that.”

She started her clothing line, Marie-Chantal, in London 20 years ago, and it is now open in the U.S. Prince George even wore one of her coats on Christmas Day last year!

Mark Cuthbert/UK Press via Getty Prince George and Princess Charlotte

“They are beautifully dressed. It’s nice to have that little touch of classic contemporary. They dress them so well,” she says of George and his sister Princess Charlotte. “I’m really lucky. There is nothing better than seeing children wearing your clothes.”