The 28-year-old singer, who welcomed her first child with fiance Jason Bell, took to Twitter to announce the news on February 10, reported Daily Star.
"I am overjoyed to let you know our little girl is here. She is amazing! I love being a mammy and will fill you all in soon. Love Nadine," she tweeted.
Former bandmate Cheryl Cole congratulated the couple by posting, "It is official. There is a baby Aloud! Congratulations Nadine Coyle now and Jason so amazing!!"
Nadine and Jason first started dating in 2008. It is the second time the couple have been engaged, after the first ended in June 2011.