Jennifer Connelly and Paul Bettany welcomed daughter Agnes Lark on May 31, but the newborn hadn't been seen in public until the couple took their older children to school in New York City on Monday.
Baby Agnes is the third child for the couple, who joins big brothers Stellan, 8, and Kai, 14 (from Connelly's previous relationship with photographer David Dugan).
After meeting on the set of 2001's A Beautiful Mind, Connelly and British actor Bettany, 40, wed in a small, intimate ceremony in Scotland in 2003.
"It was something about the way that we were together," the 40-year-old actress told Glamour in 2010. "He stood out to me as someone singular and rare and beautiful, and I liked the way he was in the world. I liked the way he was with people. I liked the way he was with my son and the way he made me feel."