alpha mom
n. The dominant woman in a group of mothers.
Many readers who were orignally seduced by the prestige of belonging to a book group can't stand the countless literary battles with alpha moms and type-A personalities.
—Elaine Daspin, “The Tyranny Of the Book Group,” The Wall Street Journal, January 15, 1999
A group of children I ran into at a New Jersey birthday party last month described some "perfect" mothers, real and imagined. Emily, 7, wasn't sure what her mother, Deborah Miraglia, did for a living: "I think it's computers. I have to go ask her." (In fact, Miraglia is a corporate bill collector in Manhattan.) But Emily did remember the day last year when her mother made time to volunteer at the school fair: "It was great. She gave me, like, 20 tickets for games."

A pretty 8-year-old wearing overalls and a deadpan expression vaunted the alpha mom who holds the most-sought-after playdate in her third-grade class: Backyard. Dog. Full fridge. Mother who plays.
—Amy Finnerty, “Status is … for Middle-class 8-year-olds; A Stay-At-Home Mom,” The New York Times, November 15, 1998
1987 (earliest)
Of course, Jane Ann's capabilities and talents do not end with the school day. She is an Alpha Mom, Band Booster member, shares responsibilities in a family owned business and is a dedicated member of her church community.
—“Jane Ann Blasingame,” Hood County News (Granbury, Texas), December 23, 1987