Selena Gomez is celebrating today after her mum, Mandy Teefey, gave birth to a healthy baby girl.
Mandy, 36, delivered her new daughter in a LA hospital with her husband Brian Teefey and her family by her side. She had to cope with a miscarriage two years ago.
Pop star Selena, 20, revealed to her fans back on Mother's Day that she was to become a big sister, and said the news made her 'the happiest girl in the world'.
Mandy raised Selena as a single mum after she divorced from her father, Ricardo Gomez, when her daughter was five. She had Selena when she was just 16.
Selena has previously said she knew her mum struggled to raise her alone and that it was tough financially for the family.
"I remember my mom would run out of gas all of the time and we'd sit there and have to go through the car and get quarters and help her get gas because she never liked to ask my grandparents for money," Selena has said.
As news of Selena's new little sister reached Twitter, her friend and X Factor Judge Demi Lovato sent her a tweet of congratulations, writing:
'@selenagomez IS A BIG SISTER !!!!!! #CONGRATSELENA!!!!'