Selena Gomez Tweets She's Going to Be a Big Sister

Selena Gomez hit Twitter to reveal some news about her family.

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Gomez's mother, Mandy Dawn Cornett, is expecting her first child with husband Brian Teefey, the actress-singer tweeted Friday.

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“Momma and Brian are finally letting me share the news... My mommys carrying my baby brother or sister :) I'm the happiest girl in the world!” she wrote.

Her message was accompanied with a black-and-white photo of her mother and Teefey, who has one of his hands on her stomach in the picture.

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Gomez is the only child of Cornett and Ricardo Joel Gomez, who divorced when she was 5.

Gomez, known for her breakout role on Disney Channel's Wizards of Waverly Place, recently toured with her band in Canada before traveling to Northern Ireland earlier this month to host the MTV Europe Music Awards in Belfast. She was the show's youngest host ever.

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Gomez, who is dating Justin Bieber, was recently granted a temporary restraining order against a man who allegedly told his therapist that he wanted to kill her.