Meghan Meghan headed off to the airport on Wednesday after celebrating the impending arrival of her first child with a lavish baby shower in New York City — and royal experts are praising the Duchess of Sussex for embracing the American tradition.

The star-studded shower was reportedly fit for a royal. While the 37-year-old celebrated on Tuesday, the party actually took place on Wednesday at the Upper East Side hotel The Mark, Vanity Fair reported. The festivities were organized by Serena Williams, who booked out the penthouse suite, which features two floors, five bedrooms, four fireplaces, six bathrooms, as well as extensive views of Central Park. According to Tatler, the tennis pro personally covered the cost of the $75,000-a-night room bill.

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And while the Markle has flown out to the U.S. on a private jet, which is estimated to have cost over $100,000, Vanity Fair noted that the plane belongs to one of her close friends in Toronto, who covered the cost as a present for the expecting royal.

Meghan Markle in New York City. (Getty)

Royal commentator Victoria Arbiter told Fox News that while baby showers are an American tradition, the British monarchy has no trouble with the former American actress celebrating overseas because she’s not breaking a royal rule.

“There’s absolutely no reason why Meghan shouldn’t have a baby shower,” she explained. “Showers are largely an American tradition and [husband Prince] Harry, along with the rest of the royal family, would be more than happy for her to honor her own tradition and customs. Baby showers are not customary in the U.K. as friends and family usually give gifts once a baby has been born. It’s just a different way of doing things and not because of any perceived ‘rules.’ Meghan’s friends throwing her a shower is a generous gesture and no doubt the time with them in New York will have been much appreciated.”

British royal expert Katie Nicholl, who is the author of the forthcoming book “Harry and Meghan: Life, Loss and Love,” pointed out that while some critics are worried Markle is spending taxpayer funds for the extravagant getaway, it was her friends who footed the bill. Therefore, Markle isn’t flaunting her wealth as the newest member of the British royal family. And while baby showers aren’t customary, Nicholl said Duchess of Cambridge Kate Middleton’s mother and sister previously threw a party when she was expecting.

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Tennis star Serena Williams walks on stage before speaking at the Shop.org conference Friday, Sept. 14, 2018, in Las Vegas. (AP Photo/John Locher)

Serena Williams hosted pal Meghan Markle's baby shower in New York City. (AP)

“A lot has been made of how much the shower has cost, but this is not being paid for by the taxpayers, but by her friends, so I really don’t see why anyone should have a problem with it,” said Nicholl. “It is the case that a baby shower is more of an American phenomenon than a British one and I am told Meghan was very keen to have a shower and thrilled that her friends Serena Williams and Amal Clooney offered to host the party. They really pulled out all the stops and made it a fabulous celebration for Meghan.”

Royal expert Leslie Carroll said she is stunned Markle would be slammed by the press for participating in a baby shower that was hosted by her closest friends. Carroll pointed out that as a former Hollywood star, Markle is still considered to be an outsider and will be scrutinized by British tabloids for every move she makes — and it will only worsen once she gives birth this spring.

“I view this as yet another campaign or effort by the British tabloids to ‘otherize’ Meghan,” said Carroll. “She’s the first biracial American actress to marry into their royal family… [they] always need to create a villain(ess) in this thousand year-plus soap opera that is the British monarchy. Now it’s Meghan’s turn.”

And when it comes to the royal family, royal expert Marlene Koenig said they wouldn’t want Markle to give up her American traditions or close circle of friends, despite her title. And when it comes to allegedly flaunting her wealth, she said Prince William and his wife Middleton head to tropical island Mustique, “a private island for the very well-heeled,” nearly every winter for sunshine.

Meghan Markle (AP)

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“[The British royal family] knows that Meghan had a life and career before marrying,” said Koenig. “She has adapted to royal duties quite well, but she has friends who live in the U.S. — friends who are well connected, well-educated and professional women.”

“I think personally, the queen and [Prince] Charles may be impressed with Meghan’s friends because most have achieved their successes on their own merits — as has Meghan,” she continued. “The only negatives and gripes will come from the British tabloid press. They thrive on negativity.”

If there’s only one downside to the baby shower, they pointed out, is how high profile it was. Markle, along with her celebrity guests, were frequently photographed out and about in New York City as part of the celebration. Ingrid Seward, editor-in-chief of Majesty Magazine, said Markle could have benefitted from a more top-secret affair to avoid ruthless paparazzi and backlash from the press.

LONDON, ENGLAND - DECEMBER 10: Meghan, Duchess of Sussex on stage during The Fashion Awards 2018 In Partnership With Swarovski at Royal Albert Hall on December 10, 2018 in London, England. (Photo by Tristan Fewings/BFC/Getty Images)

Meghan Markle, Duchess of Sussex (Getty)

“Baby showers are now regular events here in the UK as they are in the US,” explained Seward. “Not everyone has them but almost. Certainly, the Duchess of Cambridge had one, but it was very private, and we had no idea who attended. I am pretty sure [Princess] Diana didn’t have one, as they were not so fashionable then, but I think Fergie did and the Countess of Wessex. They are, of course, an American invention, which has crept over here in the last 20-30 years. They are not considered in any way vulgar for members of the royal family to enjoy, just a nice way for friends to be able to say congratulations.

“It is a little unfortunate it was so high profile and she was seen flying in and out on a private jet. But it would have been privately funded and nothing to do with the British taxpayer, so I see no reason for her not to have fun and enjoy it all, which she obviously did.”

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“Meghan’s [baby shower] has been unusual in how public it has been,” added Nicholl. “It has felt quite celebrity with all the paparazzi and high-profile names in attendance.”

Duchess of Sussex Meghan Markle with her husband Prince Harry. (UK Press Pool/UK Press via Getty Images)

But the celebration isn’t over for Markle. She, along with Harry, 34, is expected to depart on a trip ahead of the birth of their child. The voyage is said to be a working “babymoon” — a trip taken by to-be parents ahead of the birth of their baby.

Kensington Palace previously announced the royal couple will visit Morocco from Feb. 23 to Feb. 25 “at the request of Her Majesty’s Government.”

It’s not yet clear what the couple will do while on the trip, though the palace said “full details of the visit will be announced in due course.”

Markle is reportedly due in April. The couple’s child will be seventh in line to the British throne after he or she is born.

Fox News’ Madeline Farber and Jennifer Earl contributed to this report.