The former S Club 7 star posted a gorgeous black and white picture of her family on her website today (8 April) while giving fans the update.
Rachel said: "Introducing Miss Minnie Blossom Bourne. The pitter patter of (tiny) feet all 8 of them! Bursting with love xx"
The new snap shows herself, husband Alex Bourne, daughter Amelie and newborn Minnie all laying in a line on a bed with their bare feet on show.
Singer Rachel gave birth to her daughter Minnie on 1 April.
In a statement, Rachel and Alex said: "We're so happy that baby has arrived safely. Within minutes of meeting her we were totally smitten.
"Amelie is happy and 'cited to have a little sister to play with and we can't wait to introduce her to the whole family."
Rachel and Alex married in August 2009 and welcomed Amelie into the world on 16 November 2010.
Celebrities who have welcomed babies in 2014:
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