The younger Princess of York, who turns 31 later this month, took to Instagram to share her excitement about spending the day with her newborn, who came into the world just last month.
"I'm so excited to be August's mum and as you can see I'm enjoying my first Mother's Day," she wrote on Instagram on March 14.
With her message, she shared a new photo of her adorable little baby boy, who was clad in killer whale pants, a white knit jumper and cat and adorable bunny slippers. He as pictured lying in a lovely garden with daffodils around him, showing the royals are looking as forward to spring as we are!
"I'm also celebrating my beautiful Momma with this picture of us from March 1990," Eugenie wrote, sharing a photo of Sarah Ferguson holding her outside the hospital where she was born.
"You've taught me so much," she wrote. "Happy Mother's Day to all."
August was born Feb. 9, and proud parents Eugenie and Jack Brooksbank shared the first photos of their little lad later that month, as they posed for some sweet snaps taken at their home of Frogmore Cottage by their midwife during a home visit. August is more than a month old now, and it already looks like he's grown quite a lot!
August's full name is August Philip Hawke Brooksbank, and he's named after his "5x grandfathers," according to Eugenie, and his great-grandfather, Prince Philip. Prince Albert, the beloved husband of Queen Victoria, had the middle name of Augustus, while Rev. Edward Hawke Brooksbank is one of Jack's ancestors.
Sarah also took the time to write about how thrilled she is to be a grandmother, and also remembered her own late mother in a special Instagram post.
"To my mum, you are with me everyday and you would be so proud of your Great Grandson August," she wrote of Susan Barrantes, who passed away in 1998. She shared several lovely photos of her and her mother together.
"Thank you for all you taught me and the joy you showed me."
The Royal Family love Mother's Day, and the Cambridges also took the time to mark the important day! Prince George, Princess Charlotte and Prince Louis all wrote special cards to Princess Diana, their late grandmother, wishing her a happy Mother's Day and saying their father, Prince William, misses her.
Happy Mother's Day to everyone across the pond!