`The Fear` singer and her husband Sam Cooper - who are already parents to 14-month-old Ethel - welcomed their second daughter into the world on 08.01.13 and have named her Marnie Rose Cooper.
A source close to the 27-year-old British star told The Sun newspaper: "Marnie is a real cutie. Sam and Lily are ecstatic about adding another girl to the family. A little sister for Ethel is brilliant news to lift the January blues for the family."
Earlier this month Lily revealed she was eating lots of curry to try to bring on labour. She posted a message on Twitter, saying: "3rd curry this week... cosywomb" She also recently revealed she was going to give birth to heavy metal music.
Lily claimed her spouse had created a compilation of tracks by the now defunct thrash metal band Pantera to listen to while in labour.
She wrote on her Twitter account: "My husband is currently making me a Pantera mix cd to take to the birthing suite. #cute (sic)"
The singer was determined to take it easy while she is waiting for her new arrival. However, her relaxing routine was interrupted recently when she reached for a sweet and discovered a tin of empty wrappers.
She revealed on Twitter: "Which heathen put wrappers back in the quality street tin? (sic)"