The celebrity stylist and reality star welcomed her first child with husband Roger Berman in March, a son named Skyler Morrison.
Talking to People, Zoe revealed that she loves spending time with her baby and often finds it hard to leave him in order to tend to career commitments.
"I put a smile on his face. That's the most amazing thing I've ever done," she said.
"I don't care about anything else. I literally just stand there and stare at my baby like, 'How am I even gonna leave you for an hour?'"
She added: "I'm happier than I've ever been in my entire life. So I feel completely content and complete."
Zoe previously described her pregnancy as "wonderful [and] drama-free", insisting that it did not affect her working life.