Not surprisingly, Beyonce and Jay-Z's newborn girl is quite a looker.
Baby Blue Ivy Carter's aunt, Solange Knowles, tweeted Sunday her excitement about "the most beautiful girl in the world." (Beyonce, 30, gave birth to her baby girl in New York on Sunday, according to various outlets, including Good Morning America and her hometown paper, the Houston Chronicle. GMA reports that the superstar gave birth via C-section.)
Solange, 25, told Us Weekly in November that her big sister was picking up Mommy tricks from her. "I don't need any advice [on how to be a great aunt]," she gushed. "Because she has been a phenomenal aunt to my [7-year-old son Julez], so she's set the tone as an aunt. I've set the tone as a mom, so we're learning from each other."
As for who will be the better aunt? "Well, I'm sure my son would say she's the better aunt because I'm a mom first," Solange said. "I do realize that popcorn at 9:00 at night probably would make me the better aunt in his eyes."
Gwyneth Paltrow welcomed her close pals' newborn on Twitter. "Welcome to the world, Blue," the actress wrote. "We love you already!"
Rihanna also tweeted Saturday, "Welcome to the world princess Carter! Love Aunty Rih."
An observer at NYC's Lenox Hill Hospital told Us that Jay-Z, 42, was spotted walking the hospital halls Saturday morning looking "happy." Beyonce's family members -- sister Solange, parents Tina and Mathew Knowles -- were also spotted at the facility with "flowers with pink balloons and silver and black ribbons," the witness added.