Britain's Prince Harry and Meghan Markle leave after attending the Commonwealth Service at Westminster Abbey in London, Monday, March 12, 2018. Picture: AP

American star Meghan Markle is having to contend with a jam-packed schedule ahead of her wedding to Prince Harry.

The 36-year-old beauty - who is poised to marry the British Prince at St George's Chapel at Windsor Castle on May 19 - is trying to balance her wedding preparations with her new responsibilities with various organisations around the UK.

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A source explained: "Meghan has been regularly making private visits to organisations as she gets to know the UK charity sector."

The former 'Suits' actress has been busily attending events up and down the country since she relocated to Britain, where she's quickly become one of the most recognisable public figures.

But, at the same time, Meghan is also having to make plans for her eagerly-anticipated wedding day.

The insider told People magazine: "She's on a very busy schedule behind the scenes.

"She has her wedding preparation and is meeting a number of people all the time - from Harry's charities, staff at the household and the Royal Foundation."

This comes shortly after it was claimed that Meghan is receiving etiquette lessons on royal protocol ahead of her wedding.

The American star is said to be hard at work studying everything from how to walk to how to dress, ready for her transition into becoming a member of the royal family.

Grant Harrold, Prince Charles' former butler, said: "She has to be careful what she says, how she says it, and how it's taken because after the 19th of May, it will be a reflection of the royal family. 

"It's everyday things - from the way she walks, the way she speaks, the things she does, how she eats, how she holds her cup, how she dresses - everything will be looked at. There will be a lot for her to adapt to."