"She's here! Esti Maxine Stephens," wrote the Cravings cookbook author and model, 37. "The house is bustling and our family could not be happier."
Teigen wrote that Legend, 44, "sheds nightly tears of joy seeing Luna and Miles so full of love" while she's learned "you still need diapers with a C-section!?" Nonetheless, "We are in bliss," she added, and thanked fans "for all the love and well wishes — we feel it all!"
The photo with the post showed their mini-mes — Luna, 6, and Miles, 4 — gazing adoringly at their new sibling.
Legend shared the same photo soon after and added that he's "in awe of Chrissy's strength and resilience." He described himself as "thrilled" to watch Luna and Miles "embrace their baby sister. I’m so, so grateful, but that doesn’t seem like a big enough word..."
Over the weekend, Legend, whose real name is John Stephens, broke the news that the baby had arrived. While performing a private concert on Friday, he told the audience the baby was born that morning, calling it a "blessed day."
Calling the years since the loss "a blur of emotions," the Sports Illustrated Swimsuit model wrote "joy has filled our home and hearts again" because "1 billion shots later," while undergoing in vitro fertilization, "we have another [child] on the way." She admitted she was "nervous" to announce it to the world after suffering the pregnancy loss in such a public way. However, "everything is perfect and beautiful and I'm feeling hopeful and amazing."
Soon after, Legend said in an interview with NBC's Willie Geist that they were "ready for a new baby in our lives. It's always a bit of cautious optimism, especially when you’ve lost one before. But we really feel excited. Our kids are excited too."
Legend, who wrote the song "Stardust" about the family navigating the pregnancy loss, added, "It feels like we learned so much over the years through struggle and through the challenges that we've faced and I think we've both grown so much."