“I love u [sic],” she captioned the photo, then also tagged David Beckham and her three boys Brooklyn, 18, Romeo, 14, and Cruz, 12.
Harper eagerly sings ‘Happy Birthday’ in the video while clicking her fingers, then finished it off by blowing her mum a huge kiss to the camera.
With news that Victoria Beckham has trademarked her daughter’s name, perhaps it’s because a future singing career is on the cards?
Beckham’s fans were shocked to see how much Harper has “grown”.
“How adorable is she,” one person wrote. “I swear she was about two, can’t believe she is so grown up!”
Another wrote: “Omg she is growing into a beautiful young girl you should be so proud Victoria! What a great vid.”
Romeo and Cruz also posted selfies with their mum for her birthday with sweet messages on Instagram.
“Mum, I love you so much and hope you have the best day ever,” Romeo wrote on the caption alongside a photo of him and his mum.
“You are the most amazing mum and you are perfect in every way. I love how you make me laugh every day and whatever happens you always seem to be happy. I love you to the moon and back.”
Cruz also shared a selfie with his mum and wrote: “Dear mum happy birthday you are the best mum ever.”
The Beckham clan were also sharing snaps this weekend of their family Easter, including the introduction of a new addition: a baby duckling.