Meghan's stylist best friend Jessica Mulroney arrives in Sydney

Meghan Markle and Prince Harry are well and truly in Australia. 

Their hectic schedule includes 76 engagements across 16 days and also includes stops in Fiji, Tonga and New Zealand.

It's a daunting prospect for anyone, given the American-born Duchess's public appearances will likely be heavily scrutinised the world over. So, the 37-year-old has brought along her best friend Jessica Mulroney for support.

Yesterday, the high-profile stylist touched down in Sydney, posting an Instagram story to her followers celebrating the arrival. 

"24 hours later we made it to beautiful [Australia]," Mulroney wrote. "Only 300 or so emails to catch up on."

She was then spotted at around 6pm local time popping in to a 7-Eleven for a few snacks. Her and husband Ben Mulroney, 42, appeared to have just come out of an intense workout, donning some sweaty active wear.

"I saw her in the shop next to some Haribo treats," a witness told the Daily Mail. "Perhaps she was picking some up for Meghan's pregnancy cravings."

With up to three outfit changes a day expected from the newest Duchess, it seems the Canadian beauty won't just provide moral support, but style advice too.

Jessica and husband Ben, a TV Producer and the son of former Canadian Prime Minister Brian Mulroney, will travel in an "unofficial" capacity with the Royals, alongside their staff of ten, according to The Times.

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The stylist -- who has known and worked with Meghan since her days on the set of Suits -- will be the former actress's secret weapon on the tour.

This will prove especially handy, given the inevitable comparisons The Duchess of Sussex will get to her famous mother-in-law and sister-in-law in the fashion stakes.

"It’s her first tour. It’s all very new and quite daunting," an aide told the publication of how Meghan is feeling.

However, they noted the feminist's voice will be heard loud and clear, when she carries out a number of solo engagements during the tour.

The main purpose of the tour is Prince Harry's Invictus Games - a sporting tournament for wounded soldiers and servicement - which will be held in Sydney from Saturday.

Jessica was alongside both Prince Harry and Meghan Markle in the royal box during the Closing Ceremony of the Invictus Games in Toronto in 2017, when Prince Harry was seen chatting with Meghan's mum Doria.

The Mulroney twins, Jessica and Ben's sons became viral sensations following the Duke and Duchess of Sussex's May wedding, for their toothy grins as they walked behind the bride, carrying her veil.

WATCH: Mulroney Twins steal the show as they carry Meghan Markle's veil (post continues below)

Explaining what they were smiling about, Ben later told Canadian breakfast TV show Your Morning: "I asked him, and he said he'd never heard a trumpet before," Ben explains.

"I think when he walked in, he saw all the people there, and the flowers, none of that was there during the rehearsal.