"[This] group of American working moms screams power," says Working Mother Media Editorial Director Jennifer Owens. "They absolutely have talent, influence, status, money and smarts, but they’ve also shown the strength to overcome great obstacles, the insight to innovate and inspire, and the passion to help better the lives of others."
The soon-to-be-mom-of-two Simpson was cited for her lucrative fashion line and her role on Fashion Star. Lopez, mom to 5-year-old twins Emme and Max, was recognized for her musical achievements as well as her philanthropic side: The singer is co-chair of the Global Mom Relay, which helps bring greater medical access to mothers in the developing world. And Beyonce, "arguably the hardest working mom in show biz," says the magazine, was honored for her non-stop work ethic; since the birth of Blue Ivy last year, she's sung at President Obama's second inauguration, performed a half-time show at the Super Bowl, embarked on a world tour, and...the list of achievements goes on and on.