Kate Middleton had a sweet response for a 6-year-old girl who wished her on her birthday

When Kate Middleton turned 40, she was showered with love and wishes from all corners of the world. But only one person was lucky enough to get a reply from the royal herself. 

Mila Sneddon, a 6-year-old girl who has shared a sweet friendship with Kate since participating in the royal's Hold Still photography project in 2020, recorded a video wishing the Duchess of Cambridge a happy birthday, according to PEOPLE. 

The video was then shared on Twitter by Mila's mom Lynda. "Better late than never and home to isolate from the hospital! Wishing the Duchess of Cambridge a very happy 40th birthday from your number one fan !! Lots of love," the video's caption read. 

In the video, Mila says, "Happy Birthday Catherine! I'm so happy you're turning 40, hope you get a nice gift and love spending time with your family. Bye, lots of love, Mila."

In an unexpected move, Mila got a response from Middleton! A reply from Kate and Prince William's official Twitter account on Monday said, "Thank you Mila!"

Middleton first spoke to Mila over a Zoom call in 2020, about her photo, called "Shielding Mila," which showed the little girl waving to her dad from the other side of a window. Mila and her mother had to isolate away from Mila's father, Scott, and big sister, Jodi, as Mila was receiving chemotherapy for acute lymphoblastic leukemia.

Mila greeted Kate on the call by saying, "Good morning, Your Royal Highness." Kate responded with a laugh, "Good morning. My goodness me, you're so polite, Mila!" During the call, Kate learned that the little girl's favorite color is pink, and promised the little one that she would wear a pink dress when they first meet.

"I have to make sure I go and try to find myself a pink dress," Kate told her at the time. "Hopefully, when one day, hopefully, Mila, we'll get to meet, and then I'll remember to wear my pink dress for you."

True to her word, when the pair met for the first time in May 2021 at the Palace of Holyroodhouse in Scotland, Kate sported a color block skirt dress by Me+Em in sugar pink/bubblegum.

Mila also participated in the Christmas carol concert that Kate hosted at Westminster Abbey in December 2020. She gave a short reading during the ceremony and caught up with Kate. "She asked me what I was getting from Father Christmas and I told her I wanted a Barbie Dreamhouse," Mila said, according to Hello! magazine. "I showed her my dress and she said I looked lovely."

It sure is a cute little friendship that the two of them share, isn't it?