Former Suits star Meghan, who was wearing a Givenchy dress, was heard asking the monarch: "What's your preference?" as they decided who should climb in first.
She paired the frock with matching clutch, belt and shoes.
Lucas told MailOnline FEMAIL: 'Meghan has opted for a neutral colour once again. She wore her hair down on the windy day and paired the look with black heels and a black clutch bag.
Her Majesty's striking lime green number for her trip to Cheshire is designed by Stewart Parvin and it is teamed with a hat by Rachel Trevor Morgan.More news: Trump's trade adviser apologizes for saying Trudeau has 'special place in hell'
"I do feel her choice of an off the shoulder dress was pushing it for HRH Queen Elizabeth's Birthday celebration", wrote another on social media. They went on safaris, laid around in the sun (hence Markle's Trooping the Colour tan), and apparently went on what E! described as "outdoor adventures".
Back in 2015 then-actress Meghan Markle had travelled to Malta to learn more about her ancestry and sample the flavours of the Maltese islands.
"The role that she's taken on it's very austere, it's very sort of serious and I think there's a great weight that she has. acquired through that and she takes it very seriously", she said.
Fellow royal fan Sharon Briscoe, 61, asked to see Meghan's wedding ring before remarking on her stunning look at her Windsor wedding. Picture: GettyMeghan and McCartney worked together on the dress.
Did Meghan Markle have a royal hardware upgrade?
'This has definitely paid off for her as she looks flawless for the occasion, I would maybe like to see a bit of her old style married in with this new regal look however'.