The precious close-up snapshot shows her son's beautiful smiling face as he sits safely in his car seat. "Kaius' first trip to the office . . . he loved meeting Team Zoe obvi #angel," the 42-year-old fashion designer captioned the photo.
Zoe announced Kaius' birth on Twitter on Dec. 22. "So excited to welcome our baby boy into the world . . . he's 7 lbs 12 oz, beautiful, healthy and we couldn't be happier," she wrote at the time. The proud mom of two also wrote on her blog: "We are beyond excited for Skyler to have a sibling and for us to fall in love all over again. We feel incredibly blessed."
The Rachel Zoe Project star and husband Rodger Berman, who wed in 1996, are already parents to son Skyler, almost 3.
The celebrity stylist doesn't seem to mind being outnumbered by boys in her home. On Valentine's Day this year, Zoe shared a picture of her sons with the caption: "Feel so lucky to have 3 Valentines forever my loves @rbermanus and my angels #skylermorrison #kaiusjagger."