The 34-year-old actress - who plays Betty Francis in Mad Men - is having "so much fun" with her six-month-old son Xander and notes he has changed her priorities to be excited about "cosy T-shirts" rather than pairs of high heels.
She said: "I am at the right age, the right time in my life, where having him is just so much fun. I feel very lucky, I think being a mother is something I was meant to do.
"There's less glamour in my life though, now that I am a mother. I get more excited about cosy T-shirts than about an amazing pair of heels. That is sad. But your priorities just change."
The blonde beauty can't imagine being without Xander - who's father she hasn't revealed - so takes him to work with her and cuddles him at every possible opportunity.
She added to Britain's Grazia magazine: "I'm lucky I have a job where I can bring him to work, so I was still able to nurse him, and I could run over to see him and squeeze him when I missed him, which was often. I can't imagine having to be away from him."
