Last month, Una and her husband Ben Foden welcomed the latest addition to their family, their son Tadhg.
And while the proud parents have made no secret of the fact they are besotted by their little boy, it seems their daughter Aoife, three, is just as smitten!
Taking to Instagram, Una proved her little girl has taken on the role of doting big sister now little Tadhg has arrived.
In a new photo of the pair together, Tadhg can be seen cutely staring up at Aoife as she gently places a hand on her baby brother's face.
Dressed in a heart-patterned onesie and with half her hair tied back into a ponytail, Aoife looks just gorgeous as she leans into the newborn.
SO sweet, right?!
Letting her photo speak for itself, Una left her latest post without a caption - but that didn't stop her followers commenting on how cute her two children are.
Una's photo of Aoife and Tadhg comes after the 33-year-old showed off her baby boy in all his glory with a series of snapshots.
In one shot, six-week-old Tadhg can be seen yawning away, while in another he is cutely posing open-mouthed for the camera.
Getting used to having him around, Una recently told fans her "heart could burst" with how in love she is with her son.
The Irish beauty gave birth to Tadhg on 2 February, with husband Ben confirming his safe arrival on Twitter shortly after.
He tweeted: "Tadhg John Foden has been born! Mum and baby are both amazing and healthy. He has a full head of hair and his mummy's lips! #babybenuna."
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