The Invisible Mother : THE PLAYGROUP: Three Women Contend With the Myth of Motherhood, <i> By Nina Barrett (Simon & Schuster: $21; 208 pp.)</i>

Jeez, don’t the rest of you sometimes wish we’d just shut up and take care of the kids? It was so much quieter back when we were little girls, in the 1950s and early 1960s, when the sounds of our mothers’ discontent were limited to a little late-night bruxism and the solitary scratching of Betty Friedan’s prophetic pen.

But then the women’s movement shoved open the door of possibility, and a rowdy crowd of dames stumbled into a new future. We could do anything: We could mimic men and stampede up the ladder of success (to a point, we would later learn, but nobody knew that at first); we could postpone childbirth until we owned fewer eggs than a foreclosed farmer; and if we wanted to we could have it all. Career, kids, happiness.

Except . . . guess what? Most women hit their late 30s and 40s feeling not that they had it all--but rather, to their exhausted, brain-shredding dismay, that they had too much, and none of it quite the way they wanted it. Having a career meant not seeing enough of the kids; having a kid meant not being committed enough to a career, and the husband, too often, took the backseat.

So a new breed of women emerged: the stock-takers, determined to make sense out of chaos. Writer Nina Barrett is one. Her first book, “I Wish Someone Had Told Me,” was the story of her first pregnancy and her early experiences as a mom. “The Playgroup” is the story of Nina and her son Sam, and the two other women who met weekly for a play group--Grace and her daughter Phoebe, and Angie and her son Gabriel.

Barrett speaks for a disenfranchised group, the mothers who stay at home, not because they are economically or emotionally predisposed to do so, but because circumstance conspires to remove them, at least temporarily, from the work force. Barrett showed up very pregnant for her New York Times job interview and was greeted by a less-than-enthusiastic interviewer. When her son Sam turned out to be a colicky baby, she put her dreams of a journalism career on hold and eventually started writing about what she knew: momhood. Grace wanted to be a theatrical director, but there was no way she could dovetail long evening rehearsals with Phoebe’s nurse-on-demand schedule. And Angie, the most troubled of the three, took on parenting as her full-time career, with a passion that would eventually be her undoing.

Barrett didn’t see their play group as a book project while it was going on; when the light bulb went off in her head she backtracked and tried to reconstruct the triangular friendship, based on interviews with her friends and a lot of her own well-footnoted soul-searching. Her method is responsible for the book’s rolling structure: Grace’s vivid memories of her first childbirth almost demand that it be the scene that opens the book, while the three fathers, who exist only in the women’s reminiscences, are painted in pale watercolor gray.

And much of what transpires is meant to serve as the narrative foundation for Barrett’s philosophical musings--her genuinely heartfelt attempt to make sense of an event that should have thrilled her but instead made her feel isolated and confused.

Now, one rather demanding friend rejects the notion of reconstructed reality altogether, his objection being that any two people will remember a conversation differently five minutes after it’s over. I don’t go that far--since wonderful books like “Indecent Exposure” depend on recreated dialogue--but I find I do have a little trouble with a whole book of remembered material. I guess it’s a memoir, more than a book of reportage.

That’s my real dilemma. Heaven knows, we could afford to pay a little attention to the plight of American moms: Society still tells us that the best mom is the full-time mom, yet women who assume that role, as Barrett did, become instant “disappeareds”--ignored, or, if noticed, often ridiculed and resented. Working moms have the unenviable opportunity to live their lives feeling they’ve done nothing as well as they might.

But it is a societal issue, not the fault of any single individual, and that is why Barrett’s focus bothers me. For all her talk of the big picture, her book is devoted, finally, to a microscopic examination of three women’s lives. Some narratives manage to leap to larger meaning, often because of the writer’s ability to see universal truths in tiny details; Tracy Kidder’s books about everything from computers to home-building to old age always manage to resonate with meaning. Barrett has written a more narrowly focused book, one that is often crystalline, thoughtful and articulate, but finally smaller than the subject demands.