Selena Gomez is officially a big sister! According to various reports, Selena's mom, Mandy Teefey, gave birth to the singer-actress' first sibling yesterday in Los Angeles. There's no official word on the sex of the baby, but photogs did snap a visitor entering the hospital with a balloon that said 'New Little Princess,' so most are guessing the addition to the family is a baby girl. Among the visitors to the hospital to see the new bundle of joy, was Selena herself, who was spotted outside of the medical center wearing comfy sweats. The triple threat's longtime friend Demi Lovato was one of the first to hit twitter to send her love saying Congrats Selena, Mandy and Brian. And the love didn't stop there -- in fact, Selena's dedicated fans even managed to make the news a trending topic on Twitter. As I mentioned, this is the first sibling for Selena, and the first baby for Mandy and Brian Teefey, who married in 2006. Selena revealed the news of her mom's pregnancy, very fittingly, last month on Mother's Day..