The couple, who have been dating since late 2008, revealed that they were expecting a child in September last year. Aoife, a traditional Irish name meaning 'beauty', weighed 7lbs 13oz.
England rugby star Foden confirmed the news on Twitter, writing: "I am officially a Dad!!!!!! Una an baby are both amazing and healthy!!!! So proud of them both! #babybenuna (sic)."
The Saturdays' official Twitter account added: "HUGE congrats to @unahealy & @ben_foden on the birth of their baby girl! Your aunties Frankie, Mollie, Roch & Ness CAN'T wait to meet u."
Meanwhile, Healy's bandmate Rochelle Wiseman congratulated the new father, tweeting: "A beautiful girl has entered the world today and, I'm her aunty #blessed I'm so proud of @unahealy @ben_foden BIG love! Xx"
Frankie Sandford said: "Congrats. So excited!!! Big hug... Don't forget Una on mothers day Sunday! How cool. Ur mum and dad! X."
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Vanessa White said that she was "so happy" to hear the news, while Mollie King commented: "Congratulations to my beautiful @unahealy and @ben_foden! I couldn't be more proud! What gorgeous parents u will make! I want to seeee her!"
The Irish singer confirmed that she and Foden had become engaged during The Saturdays' gig at Wembley Arena in December.
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