Prince George, Princess Charlotte and Prince Louis have paid tribute to their "Granny Diana" on Mother's Day, and said: "Papa is missing you."
Cards made by the young children included hand-written heartfelt messages to their grandmother Princess Diana.
Five-year-old Charlotte's read: "Dear Granny Diana I am thinking of you on Mother's Day. I love you very much. Papa is missing you. Lots of love Charlotte xxxxxxxxx."
Her seven-year-old brother George's card said: "Dear Granny Diana, Happy, happy mothers day. I love you very much and think of you always, Sending lots of love from George xxxxx."
The youngest child, Louis, aged three next month, painted a big heart with animal stickers.
Referring to the ongoing coronavirus pandemic, Kensington Palace acknowledged Mother's Day would be "different once again" this year, adding that many people will be looking forward to a time in the not-too-distant future when they can give their mother a hug again.
And in its official social media Mother's Day message, the palace added: "But for those experiencing bereavement, today may be particularly challenging.
"Each year on Mother's Day, George, Charlotte and Louis make cards remembering their Granny, Diana, for William.
"Whatever your circumstances, we are thinking of you this Mother's Day," it said.
Princess Diana died in the early hours of 31 August 1997, after being involved in a car crash in the Pont de l'Alma tunnel in Paris.