The swimsuit model and actress tied the knot with Roddick at the tennis player's home in Austin last year.
Speaking to E! Online's Marc Malkin, she said: "Not to name-drop, because that's really lame, but I ran into Fergie one time and she said to me, 'Once you get married, people are going to ask, 'When are you having babies?' So just get ready for it. It's going to be so annoying'.
"And she's so right. So my answer is, we're obviously waiting. We're young and we're focused on our careers and being together right now."
The Sports Illustrated cover girl - who recently filmed the comedy Just Go For It alongside Jennifer Aniston in Hawaii - added that she is looking forward to taking a break and spending time with her husband over the summer.
Roddick is currently in London preparing for the Wimbledon tournament.