GETTING BETTER ALL THE TIME By Liz Carpenter Simon and Schuster. 304 pp. $17.95

LIZ CARPENTER'S Getting Better All the Time is an interesting contrast to Jimmy and Rosalynn Carter's Everything to Gain: Making the Most of the Rest of Your Life. Stiff, cold, preachy, the Carter book proved that ex-First Families have very little to say to most retirees, who have lost the anchor of being needed, whose reflexes are as untrustworthy as their incomes, and who try to make jokes as they turn to the obit page every morning.

Liz Carpenter is a different cat entirely. Sure, she hobnobbed with the powerful -- five years in Lyndon Johnson's White House; one year as assistant secretary of education under Carter -- and she remains something of a playful name-dropper. But she also remains just plain folks, and in retirement she knows exactly who and what she is: a moderately old (66), fat or "lovably round," as she puts it (5 feet 1 inch and "anything between 160 and 195 pounds"), witty, cocky, earthy, immutably Texany Texan.

Jimmy and Rosalynn could give all the peanuts in Georgia for writing lessons and never turn out the kind of friendly prose that apparently comes easy to Liz (such familiarity is absolutely automatic by the end of the book), who writes with a great sense of place and humor.

She sits in what she says will be her last home, on a hill overlooking the Colorado River and the Austin skyline, and muses:

"What do I mean in the infinite scheme of things? And what am I doing at this hour of the morning with demanding deer who eat $42.75 worth of corn each month? Why am I out here in my rainbow nightgown and airline slippers tiptoeing around my front yard to fill six deer pans? . . . What is a loving, sexy, sophisticated, wonderful woman like me doing catering to the whims of deer?"

I'm not giving a blanket recommendation. With the random charm of Getting Better comes a lot of froth. The only important information I got from it was that if you put the avocado seed in the guacamole salad, it keeps it from turning dark. Also, there's a scarcity of good gossip. What do we learn from Liz's circulating in Washington society? Only that Walter Lippmann served cocktails in empty peanut-butter and jelly glasses.

But Getting Better will appeal to a lot of people: the millions of elderly widows who are wondering why the hell the world -- and particularly eligible men -- can't see them as just as attractive as they feel inside; the herd of zealots, among whom I count myself, who think Austin, Texas, was once the greatest city on earth and the University of Texas its greatest hangout; and those strange groupies who will read anything written by anybody who was once close to a president.

That last group will get meager fare indeed. Lyndon Johnson is scarcely mentioned and one may fairly conclude from the evidence here that the only memorable thing Liz ever did for him was to write the 58 words Johnson spoke when he arrived at Andrews Air Force Base after Kennedy's assassination.

THE OTHERS will do better. Liz introduces us to her ancestors -- the Sutherlands, the Rogerses, the Robertsons -- who played important roles in the founding of the nation of Texas, and traces her own roots back to the 24-room (no bath) plantation house in Salado where she spent her early childhood.

Her mother, who comes across as attractively headstrong, packed up the children (father was off in West Texas working) and moved them to Austin for a better education. Of the family album photos in this book, my favorite is the one with the UT tower in the background, and in the foreground young Liz, dressed in cap and gown -- and (without accompanying explanation) barefooted.

Ah, the changing morals that a 66-year-old has seen. Liz's first assignment as a reporter for the Austin paper was to interview Texas's Democratic National Committeewoman in her room in the Driskill Hotel. "I had never been in a hotel in my life," writes Liz, "or even walked through the lobby without my father. You didn't want to be seen there in those days; hotels had a negative connotation." She found the committee woman smoking and drinking. It was the first time Liz had ever seen a woman smoke, except in the movies, "and I had never been around people who drank, not even eggnog at Christmas." But there would be many more smoke-filled rooms and they would supply "some of the best times of my life," she tells us, but unfortunately without elaboration.

Not surprisingly, the strongest recurrent theme in Getting Better is loneliness. For three decades Liz and her husband Les ran a news bureau in Washington. He died more than a dozen years ago, but she hasn't come even close to getting over the loss. And apparently she hasn't come close to replacing him. Again and again she returns to the problem of how to "make men appreciate the appeal of women over fifty." She has no answer. But her brother Tom, mildly famous in some six-pack circles as a philosopher, came up with a pretty good suggestion: "There ought to be a law that after fifty, men and women meet only in total darkness like the fish in Mammoth Cave."

Perhaps Liz scares men away. She evidences no shortage of ego and she admits that she may "give the impression of being formidable." The Equal Rights Amendment, for which, she tells us in some detail, she labored valiantly, might be useful to your run-of-the-mill woman, but I imagine Liz Carpenter needs its protection about as much as T. Boone Pickens needs Social Security.

Still, Mr. Right would be rewarded by what must be great parties -- even allowing for Liz's exaggeration -- and some memorable moments in her orgy-size hot tub.

Robert Sherrill is a visiting journalist in residence at Duke University.