Thelma and Louise, 30 Years Later : LIFE ESTATES, <i> By Shelby Hearon (Alfred A. Knopf: $22</i> ;<i> 231 pp.)</i>

Shelby Hearon’s 13 novels mark her as a feel-good writer. Any representative sampling of her work would include the sunny “Hug Dancing” (1991), the hilarious “Owning Jolene” (1989) and the sharp-edged “Small Town” (1985). All strike a delicate balance between poignancy and high comedy. “Life Estates” is no exception; it glows with Hearon’s characteristic wit and compassion even while it explores an uncharacteristically somber topic: mortality.

Throughout her entire body of work runs one consistent clarion call: However beset we are, however vulnerable, it behooves us to thumb our nose at fate, take control, change what’s changeable and make the absolute best of what cannot be changed.

It is a message echoed, loud and clear, by 55-year-old Sarah Cooper, the feisty feminist narrator of Hearon’s latest novel. It is echoed again, faintly, almost too late, but with great gallantry, by Sarah’s eternally young-at-heart friend, Harriet Sloane.

Sarah and Harriet have been buddies ever since they boarded together at Miss Pritchard’s, “one of the country’s best marriage preparatory schools.” Although Sarah lives in the Blue Ridge Mountains of South Carolina and Harriet in east Texas, the amazing symmetry of their lives has kept them close.

“I mean,” marvels Harriet, “(We’ve) been in each other’s weddings, married bankers, had our boys and then our girls the same years, got separate bedrooms at the same time. . . .” They have, in fact, walked each other’s lifelines for 40 years, phoning one another often, exchanging twice-yearly visits. And now, just months after Sarah’s husband has died of cancer, Harriet’s husband perishes in a car crash. “Life Estates” gets underway as the two women confront widowhood--separately and together.

Looking back on her life, the newly widowed Sarah wryly acknowledges the irony of her marriage. Just out of school, she plunged into matrimony with handsome hunk Nolan because she thought him sexually exciting. It took her some years to realize that he was insensitive to all her needs, sexual and otherwise.

Making a tolerable accommodation to marriage, Sarah staked claims to freedom and fulfillment elsewhere. She took long drives through the lovely countryside to commune with nature. She gardened with passion. Eventually she co-founded a custom wallpaper business, servicing the area’s old historical homes and catering to the women who treasure them. As the business flourished, Sarah even persuaded her jealously paternalistic husband to agree to separate tax returns and separate checking accounts. Freedom indeed.

After his death, Sarah breaks the last bond with control freak Nolan by rejecting the “life interest” he bequeathed her against her explicit wishes. Like her approving mother, an elderly entomologist off to study rare spiders in the Patagonian rain forest, Sarah knows how to seize the day.

Once she is released from the bondage of a lousy marriage, Sarah relishes the new freedoms widowhood offers. She particularly savors new-found intimacy with a 70-year-old doctor who has admired her for years. Unlike Nolan, he provides her with understanding, companionship and good sex.

By contrast, Sarah’s friend, the petite and gorgeous Harriet, is devastated by her husband’s death. Outgoing and popular, Harriet “could have been dropped at the North Pole and had a dozen chums by nightfall.” For years she has spent every weekday morning with the 11 women friends of her “Birthday Club.” Like Sarah, she got little support from her husband and felt herself more his appendage than partner. Moreover, she discovers soon into widowhood that he had a long-term affair with a “tacky size 10.”

Adrift and scared, Harriet buys a gun for protection. She dreams of seducing an attentive younger man. She frets obsessively about her daughter, who seems determined to deny Harriet the grandchildren she craves. Harriet hasn’t a clue, Sarah realizes, as to why her own daughter rejects motherhood while Sarah’s daughter is a regular “brood hen.” Further differences between the two women, unexamined for years, gradually surface.

The friendship subtly changes, and changes drastically, when the two friends suddenly find themselves face to face with their own mortality, too. That it survives, as strong as ever, is a tribute to the resilience of the two women, Harriet as much as Sarah, and to the redemptive power of friendship.

Sarah may be a bit over-zealous as a feminist, a bit under-involved as a mother, but she is altogether attractive--bright, caring, strong. It is, however, the funny/sad Harriet who touches the heart and stays in the head. Around these two ultimately heroic heroines Hearon has woven yet another live affirming novel which, while not profound, is profoundly readable and satisfying.