The actor, best known for portraying Toby on This Is Us, shared the news on Instagram. He officially welcomed his baby girl to the world in a sweet video posted on the social media platform, where he also revealed her name, Aoife Bea Sullivan. “She came 3 weeks early, fully grown, healthy and VERY strong,” the actor wrote in the caption, noting, it was “a super fast and smooth delivery (much to her mother’s relief).” “Brother Bear is enamored and overjoyed to welcome his sister home, telling everyone “baby coming!” the day she was born,” adding, “she has immediately captured our hearts and doubled the love. 💕 The video shows the sweet newborn wrapped in a white blanket and donning a floral tiny hat. “Hi… I’m Aofie, I’m new here,” the text over the video overlays. Footage also shows Sullivan holding his daughters little foot, the beaming parents introducing their 2-year-old son to his baby sister, and the bundle of joy hanging out on the couch with her dog, Harry. And the This Is Us family continues getting bigger and bigger as the news comes just days after Sullivan’s former co-star, Mandy Moore, announced the birth of her second child. The 38-year-old announced the arrival of Oscar Bennet Goldsmith or “Ozzie” on Friday, Oct. 21, along with a series of precious photos of the new babe. In the caption, she noted he “arrived a little late but with much aplomb (and an easier/speedier delivery than his big brother, much to the delight of his parents)."  More News: ‘The Mole’ Finalists Talk Through the Season’s Biggest Moments and Unseen Alliances Bill Nye Shares Throwback Photos in ‘Teenage Dirtbag’ TikTok Trend Rosie McClelland Congratulates Her ‘Beautiful Cousin’ Sophia Grace Brownlee on Her Pregnancy