Prince William and Kate Middleton Share Letters Their Kids Wrote to "Granny Diana" for Mothering Sunday

• In a new post on social media, Prince William and Kate Middleton revealed that their three children, Prince George, 7, Princess Charlotte, 5, and Prince Louis, 2, all create sweet drawings and letters for their late grandmother Princess Diana on Mothering Sunday each year.
• The couple shared the children's drawings and letters to their "Granny Diana" on the official Kensington Royal Instagram account Sunday morning.
• In her sweet letter, Princess Charlotte even acknowledged how much her dad misses his late mother, writing, "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 xxx."

Prince William and Kate Middleton are honoring Princess Diana for Mothering Sunday.

People across the United Kingdom are celebrating Mothering Sunday today. Like Mother's Day in the United States, Mothering Sunday is a day to honor mothers for all they do year-round. In a post on the officially Kensington Royal Instagram account today, William and Kate revealed a sweet tradition in their family.

In addition to honoring their own mother, the Cambridge kids also set aside some time every year on Mothering Sunday to pay tribute to their late grandmother, Princess Diana, apparently. Will and Kate shared the sweet drawings and letters that Prince George, 7, Princess Charlotte, 5, and Prince Louis, 2, drew and wrote for their grandmother, who they call "Granny Diana," this year.

In his letter, George wrote, "Dear Granny Diana, Happy happy Mother's Day. I love you very much and think of you always, sending lots of love from George xxx."

As sweet as that is, however, Charlotte's letter may have even topped it. The five-year-old acknowledged how much her dad misses his own mother in her sweet letter, which was accompanied by a drawing of a heart.

"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 xxx," she wrote.

Two-year-old Louis wasn't left out. The Cambridges shared a heart-shaped piece of art the toddler made, along with his own squiggly signature.

Will and Kate explained the significance of the day and their children's sweet tradition in the post's caption.

"This year Mother’s Day will be different once again," the royals explained. "Many of us will be apart from our loved ones, but looking forward to a time in the not too distant future when we can give our mother a hug again. 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 💐."

Happy Mothering Sunday to all of the moms out there.