And with our total blessing and understanding, she is said to have opted for a totally fuss-free, feet-up, stay-at-home celebration rather than a big limelight affair.
St James's Palace has said the Duchess will be marking her birthday 'privately'.
It's thought the 12 weeks pregnant Duchess of Cambridge is with her husband Prince William at their home in Anglesey, North Wales, where the Duke works as an RAF Search and Rescue helicopter pilot. We hope he'll be making Kate a romantic birthday meal.
But no soft cheese or raw eggs, eh, Wills? She's suffered enough sickness after being hospitalised with hyperemesis gravidarum a few weeks ago.
Happy birthday, Kate.