Meghan Markle and Prince Harry Wish Princess Charlotte a Happy Birthday Amid Royal Baby Watch

Prince Harry, Meghan Markle
Jo Hale/Redferns

The Duke and Duchess of Sussex are expecting their first child any day now!

Princess Charlotte is getting some birthday love from her aunt and uncle!

On Thursday, Prince Harry and Meghan Markle expressed their love for their niece on Instagram by commenting on one of the photos Kensington Palace released in honor of the young royal's fourth birthday.

In the pic, an adorable Charlotte is sitting on a fence while sporting a grey sweater and plaid skirt. Prince William and Kate Middleton's middle child has a sweet smile on her face in the pic, which was taken by her mom.

"Happy Birthday Charlotte!" the comment from the Duke and Duchess of Sussex's record-breaking Instagram account read. "Lots of love, H and M xo."

Instagram

Harry and Meghan offered similar sentiments to Charlotte's younger brother, Prince Louis, when he celebrated his first birthday late last month. "Happy Birthday Louis! Sending lots of love from both of us. xo," they wrote at the time.

The comments from the royal couple come amid mounting anticipation for the birth of their first child. Last month, a source told ET that the Duchess is due "any day now" and is "enjoying her pregnancy and anticipating the days ahead."

"It is such a happy and exciting time for Meghan," the source said. "She looks absolutely radiant and is taking each day at a time. [She is] looking forward to becoming a mother."

Though the birth could happen any time now, royal fans won't know exactly when Baby Sussex makes his or her arrival. Meghan and Harry announced that -- unlike Prince William and Kate Middleton -- they will not pose for photos with the newborn outside of the hospital. Rather, they'll share photos taken on the grounds of Windsor Castle at a later date.

"Meghan Markle does not want the pressure of having to pose on the steps for cameras so soon after childbirth," a source recently told ET, adding that, while the couple is "extremely excited" for the birth of their first child, they intend to “enjoy the magic of childhood without any undue expectations."

Watch the video below for more on the growing family.

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