Prince Harry and Meghan Markle (in The Line and P.A.R.O.S.H.)

Meghan Markle is American-born, but her loyalty for Canadian designers could be seen in what she chose to wear for Monday’s announcement of her engagement to Prince Harry.

Beaming beside the prince, Markle officially greeted the worldwide media wearing a Line belted coat, a P.A.R.O.S.H. green dress, Aquazzura heels and Birks 18-karat gold earrings. The coat and earrings came from companies based in Canada, the adopted country of the “Suits” actress, who shot the USA Network series there until she recently relocated to London.

Having met Markle a few times at various events in Toronto and having sat beside her at a dinner in honor of Roland Mouret, Noreen Flanagan, editor in chief of Canada’s Fashion magazine, said, “I was really charmed by her and came away quite impressed by just how smart she is and how she has that graceful confidence that I always envy when I see that in a woman.”

Markle and Mouret “clearly had an affection for each other,” since she has worn his clothes on the legal drama, Flanagan said. But the Los Angeles-born Markle has also made a point of wearing an assortment of Canadian labels, many of which she discovered through her stylist Jessica Mulroney — Sentaler, Aritzia, Mackage, Reitmans, Soia Kyo, Pink Tartan and Smythe. Earlier this year, Markle guest-designed a work-to-weekend collection for Reitmans, modeled in its campaign and readily gave her two cents about how she felt and what she thought. Flanagan said, “We think of her as a honorary Canadian as she lived here for years while she filmed ‘Suits.'”

Mulroney and other friends in Markle’s inner circle like Misha Nonoo, Legend of Lido cofounder Benita Litt and Pilates Platinum founder Heather Dorak did not respond to requests for comment Monday. But executives at Line and Birks discussed the Markle effect on their sales.

The white $750 Line sold out “within minutes” Monday by midmorning and the brand’s site crashed more than once Monday due to the interest. But re-cuts are already underway and the company should be able to meet whatever demand is requested, according to president and cofounder John Muscat. “We’re not a huge company and it’s the end of the season so we don’t stock a lot of these coats. They are all handmade.”

Markle didn’t have to pay for the $750 white Line coat — the company gave it to Mulroney as a gift, Muscat said. But the “Suits” actress has been a big supporter and client of the Canadian brand, and actually has the same style in the four other colors that it’s offered in — burgundy, black, light gray and soft pink. (As of next fall, she could add a hunter green one to her personal collection.) The style has also been renamed the “Meghan” in honor of the incoming royal. Line has worked with Mulroney and Natasha Koifman, president of NKPR, to help Markle with her style choices in recent years.

Muscat found out that Markle chose a Line coat while he was getting ready for work Monday morning. “I don’t know how you’re supposed to react to that. I was surprised that she chose to wear our coat for such an incredible announcement. I was really honored and touched that she did that. She’s bringing a little bit of Canada with her to London,” Muscat said. “She particularly loves this coat. She has it in every color so that makes a little sense. She wears it like a second skin.”

In the aftermath of Monday’s announcement, Birks had seen more than a 50 percent increase in web site traffic by early Monday afternoon, said Birks brand chief marketing officer and vice president Eva Hartling. “On the good side, our site can sustain heavier traffic,” she said. “We’ve also had a lot of inquiries from stores mentioning that clients either called or walked in asking to see the $780 18K gold Opal earrings from the ‘Les Plaisirs’ collection.” The opal stones are meant to stimulate the wearer’s creative energy, Hartling said. Mulroney pulled and purchased several pieces recently but Birks executives did not know if anything would be chosen for Monday’s big news.

With 30 Birks stores in Canada and distribution in about 40 doors in the U.S. and U.K., Birks expects to sell a few hundred units of the earrings that Markle wore, Hartling said. Having launched Birks fine jewelry in the U.K. last month through a deal with Mappin & Webb, the retailer promptly ordered the earrings after seeing Markle wearing them. “The timing obviously is great for the announcement today. While the news of the engagement is very vibrant all around the world, it is very much so that way in the U.K. and London,” she said. “For now, the collection is only available online for Mappin & Webb, but we expect it will be in the stores shortly.”

Markle has sported Birks jewelry before — most recently at the Invictus Games in Toronto where she wore a gold and diamond ring on one of her thumbs. Her soon-to-be sister-in-law the Duchess of Cambridge also wore Birks and Line during the royal visit to Canada last year. Whether Markle and Prince Harry will follow Kate Middleton and Prince William’s lead again regarding their official engagement photo remains a question mark. A spokeswoman for Mario Testino who took the official one for Prince William and Middleton did not respond to a request for comment Monday.

Two sets of photos of Markle with Prince Harry were posted on the P.A.R.O.S.H. by Paolo Rossello Instagram account Monday to show the sleeveless and long-sleeve versions of the P.A.R.O.S.H. sleek hunter green dress with a bow on the left hip that she wore for Monday’s announcement. The label, an abbreviation for “Paolo Rossello Second Hand,” is known for its secondhand fabrics and trans seasonal looks. Rossello’s take on vintage is a compilation of designer brands with unusual finds and military styles. Executives at his company, as well as those at Aquazzura, did not respond to a request for comment.