A star was born! Beyonce and Jay Z, who married in April 2008, welcomed their first child early this year, a baby girl named Blue Ivy Carter. "Her birth was emotional and extremely peaceful -- we are in heaven," the proud parents gushed. "It was the best experience of both of our lives." Beyonce's sister Solange Knowlescalled the baby "the most beautiful girl in the world," while pal Rihannatweeted: "Welcome to the world princess Carter! Love, Aunty Rih."