The charity work Meghan will now leave behind her

Miss Markle’s warm-hearted nature and her desire to make a difference were clear to see in video, filmed on a trip to Rwanda with World Vision Canada last year.

The American actress is shown dancing with youngsters and crouching down to talk to children, giving them hugs, and helping to drill a borehole to provide clean water.

“I do think that it’s these tiny acts of generosity or grace or even just understanding that allow us to really make a difference on a much larger level,” she says in the film.

William, her soon-to-be brother-in-law, who is on an official visit to Finland, spoke of the joy his family feels for Harry and Meghan and wished them “all the happiness in this very exciting time”.

Harry has said that “all the stars were aligned” when he met and fell in love with Miss Markle, and her parents Thomas Markle and Doria Ragland have testified to her nature as has “a kind and loving person”.

In the footage, when she hears how one girl called Florence has dropped out of school because she has to walk for hours a day to collect dirty water, which is also making her sick, Miss Markle, who is listening intently, tells the youngster: “I’m so sorry.”

She is seen helping to turn a manual drilling rig to make one of the new wells.

“It feels really cool to be a part of this part of the process. It’s really hands on and being part of this clean water being here from everyone, it feels really nice,” the future royal says.

She adds that the new boreholes are ensuring girls can now go to school rather than spending their time travelling to collect water instead.

Miss Markle, who also had a role as a UN women’s advocate, has given up her current charitable commitments with World Vision to focus on getting to know the UK and touring the country with Harry.

But she said in her engage­ment interview that she would eventually be able to focus even more on causes that were important to her.