By Patricia Sellers

    Ever since we launched the Fortune Most Powerful Women 12 years ago, we’ve noticed that behind most every remarkable leader on our list stands another powerful woman. Call her mom.

    When I interviewed Carly Fiorina in 1998 for the first MPWomen issue (she was at Lucent (ALU) then and hardly known outside of telecom), she talked passionately about the influence of her mother, who died soon after we put Fiorina on our cover. Carly, who was No. 1 on our very first MPWomen list, went on to head Hewlett-Packard (HPQ) and is now running for the U.S. Senate in California.

    As CEO of eBay (EBAY), Meg Whitman eventually nabbed the top spot on the Fortune MPWomen list. Her mother, Margaret Whitman, died this past Monday night.

    I didn’t know Meg Whitman’s mom well, but I met her a couple of times. And I learned from what an amazing force she was, particularly for her era. During World War II, Margaret Whitman volunteered for the Red Cross and worked as a mechanic in New Guinea, fixing trucks and airplanes there.

    A true adventurer, she passed on to Meg–who is now waging a high-stakes battle to become Governor of California–her gutsy, pioneering spirit. In the 1960s, Margaret used to pile her children into a Ford Econoline van and drive coast to coast or up the Alaskan highway during summer vacations. Meg and her older sister, Anne, and brother, Hal, would camp for three months. No hotels for this clan.

    In 1973, when Meg was in high school, her mom traveled to China with actress Shirley MacLaine. Margaret Whitman was the Boston housewife in a delegation of “ordinary” American women whom MacLaine featured in a documentary, The Other Half of the Sky: A China Memoir.

    “Before the China trip, my mother told my sister to get a teaching degree–in case her husband couldn’t support her,” Meg Whitman told me. “When she came back from China, her perspective on women had changed completely. She told me, ‘Go figure out what you want to do, and do it.”

    Margaret Whitman remained a force. Nearly 30 years later, when Meg was moving eBay into Germany, her mom pestered her to invest in China first. “I told her, ‘Mom, Germany has 40 million Internet users. China has one million. Germany, 40. China, one.’” (Meg’s mom told me: “Once Meg makes up her mind, you can’t change it.”)

    Margaret Whitman was 89. The Whitman family is gathering tomorrow, but there are no formal services. We wish the family our condolences.