The actress, who gave birth to her second child in April, told US Weekly that she has been trying to convince screenwriter husband David Bernoff to rush into having their third.
"I'm really old," she said.
"David was like, 'We have to wait three years'. And I was like, 'We don't have three years! We'll be too old at that point'."
Peet explained that she is concerned about the chances for a problem pregnancy which increase with age.