“BeaBea you are sensational and I have loved every minute watching you be brave and true… and you… and now a mummy to be.”
She then signed off the message with a smiley face and #iloveyou.
The video also featured the song This Is Me from musical drama film The Greatest Showman.
Princess Beatrice was inundated with well-wishes as fans took to the post’s comment section to send her birthday messages.
One person wrote: “Happy Birthday, princess Beatrice!
“It is wonderful to see the love of real sisters like you.”
Another fan said: “The bond of sisters is truly beautiful. I too love my big sis dearly.”
A third commenter added: “Eugenie AND Beatrice are The Greatest Showman fans?
Beatrice’s husband Edoardo Mapelli Mozzi also took to Instagram to wish the mum-to-be a happy 33rd birthday.
He wrote: “Happy Birthday my love. I love you with all my heart.”
The property tycoon accompanied his message with a black and white selfie of the two of them.
Source: EXPRESS CO UK