Taking to Instagram, Meghan shared a recent black-and-white photo of the former actress tightly hugging her little girl whilst enjoying a boat ride together, alongside a throwback photo showing Meghan tenderly cradling newborn Lilibet following her birth in 2021.
In the caption, the mum-of-two penned: "Happy birthday to our beautiful girl!
"Four years ago today she came into our lives - and each day is brighter and better because of it. Thanks to all of those sending love and celebrating her special day!"
Lilibet's birth
Lilibet Diana Mountbatten-Windsor was born in California on June 4, 2021 at Santa Barbara Cottage Hospital. Her birth came after Prince Harry and Meghan stepped back from their royal duties and moved to the U.S. with their son, Prince Archie, now six, in 2020.
Lilibet's arrival was shared on the Archewell Foundation website and revealed that the newborn was named after Queen Elizabeth's family nickname, while her middle name honours her beloved late grandmother, Princess Diana.
A spokesperson for the couple said at the time: "It is with great joy that Prince Harry and Meghan, The Duke and Duchess of Sussex, welcome their daughter, Lilibet "Lili" Diana Mountbatten-Windsor, to the world.
"Lili was born on Friday, June 4 at 11:40 a.m. in the trusted care of the doctors and staff at Santa Barbara Cottage Hospital in Santa Barbara, CA.
"She weighed 7 lbs 11 oz. Both mother and child are healthy and well, and settling in at home.
"Lili is named after her great-grandmother, Her Majesty The Queen, whose family nickname is Lilibet. Her middle name, Diana, was chosen to honor her beloved late grandmother, The Princess of Wales.
"This is the second child for the couple, who also have a two-year-old son named Archie Harrison Mountbatten-Windsor. The Duke and Duchess thank you for your warm wishes and prayers as they enjoy this special time as a family."
Meghan and Harry's home life in Montecito
Meghan and Harry are raising their son, Archie, and daughter, Lilibet, at their sprawling mansion in an exclusive corner of Montecito, California, which is an A-list hotspot home to the likes of Oprah Winfrey, Katy Perry and Orlando Bloom and Jennifer Aniston.
Their impressive home boasts a number of high-end amenities, including a wine cellar, a swimming pool, a rustic kitchen and a shared home office.
In a previous interview with The Cut, Meghan revealed that she and Harry instantly fell in love with the property. "We did everything we could to get this house," said the 43-year-old. "Because you walk in and go… Joy. And exhale. And calm. It's healing. You feel free."