Aniston doesn’t specify in Allure the reason she doesn’t have kids, though she has acknowledged in the past a desire to be a mom. “I’ve said it so many times: I’m going to have children. I just know it,” she said in a 2008 Vogue profile. But who knows if she’s changed her mind, and Melanie Notkin, author of Otherhood: Modern Women Finding a New Kind of Happiness, says Aniston is smart to keep her reasons quiet. “Jennifer has done a really good job of saying, ‘It’s none of your business why I don’t have children,’” Notkin tells Yahoo Parenting.

For more of Notkin's interview, visit Yahoo Parenting.