Beyoncé Knowles gave birth to a baby girl  today in New York! She and Jay-Z  reportedly named their daughter Blue Ivy Carter. Rihanna shared in the excitement this evening  tweeting, "Welcome to the world princess Carter! Love Aunty Rih" while their friend Gwyneth Paltrow said , "Welcome to the world Blue! We love you already." We can't wait to see pictures of adorable baby girl Blue — congrats to Beyoncé and Jay-Z on this extra special weekend!