March 19, 1984 12:00 PM

If Judy Blume were the protagonist of a novel, she’d be pretty hard to stomach. Rich, famous and fresh-faced at 46, she has two stylish abodes, a devoted lover, a pair of grown children who actually like her and a new book, Smart Women (Putnam, $15.95), on the best-seller list. She knows how to tap-dance, get a good table in a crowded restaurant and inspire loyalty among millions of readers. Add to that the fact that she’s a genuinely nice person, and Blume’s story would seem to have all the dramatic tension of The Joy of Cooking.

But Blume is no one-dimensional character, and it took a long time for her to shed the notion that hurt follows happiness. The sudden death of her father (a New Jersey orthodontist) on the eve of her first wedding in 1959 convinced her that “you have to pay for being happy.” Judy’s marriage to lawyer John M. Blume, the father of her children, came to a painful end after her 16 years as a housewife in suburban Scotch Plains, N.J., and she hastily took on a second husband in 1976 because she “didn’t know how to be unmarried.” Blume lived in Santa Fe as the wife of physicist Thomas Kitchens for three years, and it was the most emotionally trying interlude she’d ever experienced. Both son Larry (now a 21-year-old Hollywood production assistant) and daughter Randy (a 23-year-old pilot in training) were traumatized by the impulsive marriage, and Blume recognized her mistake early on. “I cried every day,” she says. “Anyone who thinks my life was cupcakes all the way is wrong.”

Still she prevailed. “Work really saved me,” says Blume, whose first book, The One in the Middle Is the Green Kangaroo, was published in 1969. “I’ve always been able to write, even when everything else was falling apart.” The woman who now has an estimated 29 million paperbacks in print kept churning out such juvenile-list hits as Superfudge even while she branched out into the adult market with Wifey in 1978—the year before she finally split from Kitchens. The divorce came, she says, as “a real relief. Everything I’ve read says you have to have a mourning period after a divorce, but I didn’t. My mourning took place when I was in the marriage.”

These days Blume is an unabashedly happy woman—reveling in her relationship with a Columbia University law professor who prefers to remain anonymous, and with whom she’s lived for more than four years. There are no plans for a trip to the altar, but Judy claims that she has “never felt so married. Every day with him is a treat.”

Although Blume still loves Santa Fe and lives in her house there several months each year, she’s been intoxicated by Manhattan since the age of 9, when her mother brought her to see her first Broadway play. As soon as son Larry finished Santa Fe Prep in 1981, Blume persuaded her lover to travel with her to New York, where they settled into a low-key life. They favor neighborhood restaurants and movie theaters to high-profile haunts like Elaine’s.

As much as she loves the city, Blume says, “I still haven’t figured out life here. I overheard one woman walking down Columbus Avenue telling a friend, ‘I’m through with relationships, but lunch is okay.’ I decided that fear of intimacy is very New York—I’d written an entire musical around that by the time I’d gotten to the next block.”

For her part Blume has decided to tap her troubles away. “I had lots of dance classes as a kid, and when I came here I decided I really wanted to learn tap.” Taking class five times a week at a neighborhood studio with such professional dancers and actors as Mandy (Yentl) Patinkin, Blume has learned to savor working up a sweat. “I have to be strapped down to miss class.”

Judy’s second novel for adults reflects at least some of the changes in her own life. A thoroughly modern divorcée, Smart Women’s Margo must learn to cope with a new man and assuage her wounded offspring. Blume makes her characters’ exploits determinedly didactic. “Beneath the chatty, vernacular surface,” wrote New York Times’ book reviewer Michiko Kakutani, “her characters’ penchant for psychobabble makes the reader feel as though he were paging through the latest self-help text.”

Such criticism doesn’t bother Blume, who admits she’s more interested in sociology than in literature. “We haven’t had very much fiction dealing with the question: Can children survive their parents’ new loves? I wanted to show that you can be a sane, decent, loving human being and still get yourself in a situation that’s absolutely wrong for yourself and your children.”

Writing novels isn’t the only way she attempts to shed light on such subjects. In 1981 she founded the KIDS Fund with the royalties from the Judy Blume Diary, a children’s journal sprinkled with Blume quotations. The fund offers a total of $40,000 each year to nonprofit programs ranging from a workshop on divorce and separation at Manhattan’s West Side YMCA to support groups for teenage mothers in Sante Fe. And her next book will be a compilation of letters from her readers (they send her 2,000 each week), covering such trademark Judy Blume topics as masturbation, menstruation and dating.

A new novel for young adults is aborning too. For the moment Blume knows only that it will be about two girls living in stepfamilies and that it will be shaped, to some extent, by the continuing adventures of its author. Like her own story, it will all turn out fine in the end.