The charity aims to fight poverty in Uganda and it was set up in memory of Henry van Straubenzee, a close friend of Prince Harry who died at the age of 18 in a vehicle crash.
Henry, who was a good friend of both Prince William and Harry, passed away in a vehicle accident 16 years ago in 2002.
A friend of Mr Markle, 74, who has not spoken to her since her May wedding to Prince Harry, said he told him: "How could they be so cruel and heartless?" Last year, Prince Harry joined the former first couple at their Obama Summit in Chicago.
During the service, held at St Luke's Church in London, Meghan, 37, gave a reading from the poem "Our Deepest Fear" by Marianne Williamson.
This Christmas is Harry and Meghan's second stay at Anmer with Kate and Wills, as they also spent last Christmas at the 18th century Georgian property.
At the Middletons' home in Bucklebury, outside London, the grandchildren, who also include Prince George and Princess Charlotte, each have a Christmas tree in their room "so that they can decorate it themselves", Carole Middleton told the U.K.'s The Telegraph.
Kensington Palace is said to have launched the hunt for the source of the leaks, according to the Mail on Sunday. The site claimed the Duchess of Sussex's mom, Doria Ragland, might be joining the royals.
The royals's upcoming Christmas together dispels rumors to tension surrounding the duchesses.
And the wide-legged style is her particular favourite, worn on multiple occasions since she took up royal duties a year ago. "It is a very broad claim to be making, and is likely just gossip from palace staff".
However, it is believed that Meghan and husband Prince Harry will still be spending Christmas with the Duke and Duchess of Cambridge this year.
Soyuz Rocket Launches, Docks Successfully To Relief Of NASA, Russia Space Agency
If all goes to plan, the spacecraft is due to dock at the ISS at just after 5.30pm tonight - six hours after lift-off. EST, the Soyuz rocket launched from the Baikonur Cosmodrome in Kazakhstan.