Singer-and-actress Selena Gomez has revealed the name of her baby sister.

The 'Spring Breakers' star's mother Mandy gave birth to another daughter on Wednesday (June 12) and Gomez has taken to Twitter to reveal details of the new family addition.

She wrote: "Momma, Brian, and me are all so grateful for all your well wishes.  My lil sissy Gracie Elliot Teefey was born on June 12th.  Luv you all XO (sic)."

Mandy divorced the brunette beauty's father Ricardo Gomez when the pop songstress was five-years-old.

She then tied the knot with Brian Teefey in 2006.

Gomez's friend and fellow singer Demi Lovato used the social networking site earlier this week to pass on her congratulations to the star, 20.

She tweeted: ''@selenagomez IS A BIG SISTER!!!!!! Everyone congratulate her and her family!!!!!! #CONGRATSSELENA!!!! (sic)."

Gomez has previously gushed about welcoming another sibling into the world.

She explained: ''I want to be the best sister in the world. I'm really going to spoil the baby! I can't wait ... There's going to be a big age difference, so I think I'm going to be more like a cool aunt.''