Sharing the video to Instagram, the footballer wrote: "I mean come on this is ridiculously cute & Harper wanted to wish everyone a very Merry Christmas 🎄♥️ #ASL."
Fans also agreed that the message was heart-melting.
"I know a little sign language because I have a friend who is deaf. Harper did a great job!!
"She will make someone very happy when she comes across someone who is deaf."
"Wow!!! Well done harper for doing the sign languages in ASL! Merry Christmas to you all! Wish you can do BSL as well as I’m deaf 💜." wrote another.
"What an incredible person she already is! Can’t wait to see more of her kindness! Merry Christmas to you and your family," said one more.
Harper was recently baptised this weekend with Eva Longoria as one of her godparents.