More controversially perhaps, Ms. McGregor unapologetically puts her career first — ahead of children, husband and friends, she says. Among her top tips for women who want to make it to the top: accumulate skills (if you’ve got a mediocre degree from a mediocre university, get another one from a good one); build your network; become financially literate (not least so you know what interest rate you’re paying on your credit card debt); outsource at home and delegate at work; scrap the sentence “I can’t do it” from your vocabulary (Ms. McGregor, 49, learned how to fly a plane at 47 and how to shoot a gun at 43. “Do men take you seriously if you are 49 and have a B.M.I. of 37?” she asked. “No, but they do if you have a gun in your hand.”); and, crucially, learn to say “No.”

Success, then, is about prioritizing some things and about sacrificing others. Men have long had the luxury of focusing more single-mindedly on their careers as their wives ran the house and minded the children.