One day about a year ago Judith Exner's 4-year-old stepdaughter, Sarah, got into her car, ready to spend the weekend with her and her husband, Dan.

"Mommy," said the child to her stepmother, "my other mommy doesn't like people like you."

"I tried to explain to her," says Judith Exner now, that her mommy probably read some things about me that weren't true. But it confused her. And of course, it hurt me very badly."

But what concerns Judith Exner more is that a lot of people today feel the same way "other mommy does"

Judith Exner, nee Judith Eileen Katherine Immoor, married and divorced from actor William Campbell and now married to Dan Exner, is known today to her friends simply as Kate.

Last year, the story emerged from Senate hearings that one Judith Exner had been having simultaneous liaisons with Jack Kennedy while he was President of the United States and with Sam Giancana, the Mafia boss from Chicago who was recruited by the CIA to aid in assassinating Fidel Castro. Until then, Judith Exner was living a happy, quiet life, anonymous and prosperous in Newport Beach, Calif. She lived in a large house (complete with a pool and a pier) with her husband, her trained watchdog, and a gun under her pillow at night.

All that has changed. After the story of her affairs with Kennedy and Giancana, her relationships with Frank Sinatra and with figures from the underworld were exposed, her life became a publicity nightmare. She claims she is still followed by the FBI. She has been labeled a spy, a whore, a mistress, a party girl, a bimbo. Her book has been, she says, rejected by major publishing houses for no apparent reason after large advances were offered. She has had one review in a major newspaper and one prime-time television interview cancelled and she has been called a liar by Kennedy intimates Evelyn Lincoln and Dave Powers.

She also has been labeled an opportunist, exploiting her relationships, a crass materialist. Her sister refuses to see her or let her see her nieces and nephews, her husband's ex-wife refuses to let them see his daughter Sarah anymore. Many of her friends have dropped her. Even stores she used to patronize have declared her persona non grata.

So what kind of person is Judith Eileen Katherine Immoor Campbell Exner anyway?

There are several things to be considered here.

Judith Exner was 25 years old when she first started seeing Jack Kennedy, before he was elected President. She was single and she came from a moneyed upper-middle-class family. In other words she had a substantial amount of money of her own. Her father was a successful Los Angeles architect, her grandfather had made a lot of money in real estate in the East.

She had been married to an actor and was divorced. She had been engaged and was getting over that relationship.

She had grown up in California, had been raised in the Hollywood community with actors and actresses (Bob and Delores Hope) as friends of her family, and had met Frank Sinatra through mutual friends. It was through Sinatra that she met Jack Kennedy.

After her affairs with Kennedy was over and she began a sexual relationship with Giancana, even after that was over and after both men were assassinated, she never wrote or spoke publicly of her relationships with either of them. She remained silent for 16 years. Only after her story broke in the papers and the accusations began, she says, did she consider writing a book to tell her side.

Judith "Kate" Exner arrives with her husband at her hotel, the Watergate, and is shown to her room, a large bedroom with balcony and a living area. She quietly asks her husband to see if they can be moved to a suite. "I hate one room," she says.

One's first instinct is to stare at her out of curiosity. What is it about this woman that would attract all those powerful men?

She is of medium height, with long black hair, arched black eyebrows, pale, pale skin, heavily mascaraed black eyelashes, and incredible deep, almost irridescent blue eyes.

She is bosomy with slim hips and legs. She does resemble Elizabeth Taylor, as she has been told, and she has a soft high voice which sounds like Taylor's.

It is easy to see that Judith Exner must have been gorgeous when she was 25. But today, her experiences have of the girls. She had that trace of taken their toll and she looks every bit her 43 years.

What is more striking than her looks, however, is her manner. It is quiet, serene. There's a stillness about her, a peacefulness, a contentedness that would appeal to most men.

There also is a soft, fragile feminine quality there that almost demands protection.

There is none of the hey-boys-look-me-over appeal of an Elizabeth Ray, for instance.

There is no question that Judith Exner is hardly a genius. Her book is written with a near childlike simplicity (except those parts which seem to be written by her writer, veteran journalist Ovid Demaris).

She is forthright, simple, emotional at times, anxious and determined to tell her side of the story.

Judith Exner comes across as a rather nice, rather ordinary middle-aged California housewife. Only she's not ordinary.

Just the slightest shaking of the hand, the cool depth of those see-through blue eyes tearing up suddenly, the sensuous way she slides onto the sofa, the easy way she smiles, the everpresent bottle of her favorite Jack Daniels - belie her portrait of the California housewife.

Looking at her, if you let your imagination run away, you can almost hear strains of "You're Nobody Until Somebody Loves You," or "All the Way," to Sinatra songs of the '50s, the first Sams favorite, the second, Jack's.

You can see her in her blue taffeta sheath with matching shoes and bag, a blue necklace which should, Giancana told her on their first meeting, be diamonds.

She hasn't aged into this eara. She still wears her hair, makeup and clothes as though she lived back then.

She was a ritzy dame then, classier than the others she hung out with. She didn't dish the dirt with the rest shyness left over from when she was retiring, timid child, a mama's girl.

Only the mama's girl had grown up into a Sugar Dady's dream, a Ross McDonald heroine, a candidate for the American Tragedy.

When she smiles all that mystery comes back. Kate Exner, housewife becomes Judith Cambell, femme fatale (remember that word) mistress of the President, and mistress of the most powerful gangland boss in America.

She has almost forgotten.

She has been married to Dan Exner for two years and before that they lived together for three. Exner is 29 years old. He is a golf pro and now together the two of them have gone into property speculation and real estate which has earned them, she says, a very successful living.

They are extremely close, and she is clearly in need of his supportiveness, which he gives her freely.

At the beginning of the interview something is said which reminds her of her mother's death by cancer and she begins to cry and excuses herself for several minutes.

"I'm sorry," she says. "I'm just tired. I'm not used to this kind of exposure."

In her book, "Judith Exner, My Story," she documents her rendezvous with Jack Kennedy, down to plane tickets sent to her by Evelyn Lincoln, hotel reservations, cards sent with flowers, visits to the Kennedy's Georgetown house before he became President and visits to the White House.

There is no way, today, to know how much of what she says is the truth. She claims there are Secret Service records and FBI documents that will eventually vindicate her.

Probably the thing that angers Judith Exner most is the charge that she is the scarlet woman, the one to blame. She abhors what she considers the double standard - the woman is the offender, the man absolved.

"I think it's terribly unfair," she says. "I'm not a woman's libber. I love the fact that my husband takes care of me. I'm not ambitious. I'm not a career girl. But it stops right there. I think it's unfair, for instance that a woman or two women can't even go out to a restaurant together without having men try to pick them up, assume they are just looking for a man. It's in this area that the women's lib has been a good thing." Her voice becomes slightly heated as she leans forward.

"I was single. Jack Kennedy was married and had two children. If anyone was really the offender it would be Jack. I was a participant. Yes. And I will be held accountable for my own actions. But not for Jack's. I think that it's unfair that it's always the woman who is labeled the hooker or the prostitute - whether you have your own income or not."

Judith Exner is just that much of another generation, and has just that much left of her Catholic upbringing in convent schools that she still insists that what she did was wrong.

"I've never justified my position," she says. "I went with Jack Kennedy. What I did was wrong. Flat out wrong. But there are a million ways to justify doing something if you care for somebody. But this story has never been treated as though he did wrong. And I am trying to destroy that myth.

People often ask her if she doesn't feel guilty about the hurt she must be causing Jackie Kennedy and her children. "I don't want to hurt anybody," she says. "But I don't want to be a sacrifical lamb either. I don't want to be destroyed.

"People," she says, "have got to learn to accept their heroes as they are, as human beings with frailties like human beings. I'm not a fan of Nixon's but he's been really put through the wringer too."

She gets very upset, she says, when people ask why she has to dig up the past.

"The more that comes out the better," she says. "It's the only way to make politicians real. Somehow the people have got to get a fair shake. If we can't accept them as they are then we really are going to take a hard look at ourselves."

Both Exners claim they have been crushed by what they call "the Kennedy machine." "It's everywhere," says Dan Exner, and he relates several examples of how interviews and stories have been canceled at the last minute. He shrugs. "You can't fight city hall. But we are."

"It's obvious why none of the Kennedy people want to admit this," she says.

"Evelyn Lincoln is a very loyal person. But she could have answered very simply that I was a friend of Kennedy's and that he had many friends and it would all have died down." But by denying it all, says Exner, the Kennedy people forced her to come out and tell the story to vindicate herself.

The thing that amazes her is that, according to Exner, Kennedy himself never tried to hide their relationship. "Jack never considered being discreet," she says. "There were times and places when he wanted me to meet him that would have been so blatant I would have been embarrassed. He felt he could do what he wanted. That he was above it all. It was that trait of being above it all, that arrogance that was the key." It was, she says, why he could have her in his wife's home and in the White House, in their bed and not give it a second thought.

"There was also the belief on his part that even if I told, nobody would believe me."

She's not sure about how she felt then. "I think I thought I was in love with him. My relationship with him was safe. I was in love to the extent I could be. I think he was in love with me to the extent he could fall in love. I believe some things I hear about him now. I question others. But with all the time he spent with me he had to have some feeling for me."

There are two things which bother her a lot, even now, about her relationship with Jack Kennedy. One is her description of an incident in a hotel where he brought in another woman and suggested they try a threesome.

The other was going to see him and sleeping with him at the house he and Jackie shared.

"I went to his home two or three times. When I look back on it now I think how dreadful of me to go. But when you care . . . you have a way of rationalizing. It was a terrible thing for him to do. He should never have asked me to come to his home. There was no excuse for it. And no excuse for me to go."

For that, she says, she respects him less. "I was very conveniently kidding myself," she says.

She thinks his interest in women, his promiscuity was because "they had a very strong father. They are all constantly trying to prove themselves in every way."

Exner thinks her appeal for Jack Kennedy was simple. "I'm really very reserved," she says. "And I didn't want anything from him. Even when the FBI was following me I never told Jack. They were asking questions about Sam and I didn't want to ask him to help me."

She is anxious to get Dave Powers and Evelyn Lincoln to go on television with her or be interviewed with her so she can face them down with the story.

But it is her relationship with Sam Giancana that has garnered Judith Exner the most criticism.In her book she says she met him in Miami through Sinatra (long after her affair with Sinatra had ended she was on the periphery of Sinatra's Rat Pack, traveling occasionally with a group when the various entertainers in the group had shows to perform.

"I didn't spend that much time with that group of people," she says. "When I was with Frank I was always very quiet. I didn't really fit in. I'm not that hip, glib kind of person. I don't let go. It's just not in my nature."

When she met Giancana she was introduced to him as Sam Flood, a Chicago businessman, and it wasn't for a long while that she discovered who he really was.

"I knew nothing about Sam's CIA connections," she insists. "Absolutely nothing. It would have been foolish for him to tell me." She wasn't, she says, in love with Giancana and it wasn't until a year and a half after they met that she began to have an affair with him. "It was just emotional security," she says now. "It's hard for me to look back and see I was being used.

"I do think now I was used. It was very advantageous for him to be with the girl friend of the President. I think his professed love couldn't all have been an act. He did ask me to marry him. On the other hand he probably knew I'd say no. I'm so gullible I believed everything he told me. But Sam was on Bob Kennedy's most wanted strike force list of organized crime leaders. Of course he (Giancana) would use the knowledge of my affair with Jack as a tool."

She seems not to be uncomfortable with the fact that once she discovered Giancana's past she continued to see him. And made no value judgments. She admits she just didn't want to know all the gory details, and blithely discusses her involvement, saying, "I think I do it with anybody I'm close to. I accept them for what they are to me. Not for what others think about them." And she will also admit that attitude has been "rather damaging to me."

Judith Exner seems to be an apolitical woman who acts mainly on instinct and intuition. But she will say this: "I'm a disbeliever."

"I really don't think there's any such thing as an honest politician. I think they're all controlled by others."

Judith Exner has received, she says a $1,000 advance for her book and has yet to sell the paperback rights. Whatever money she does make on the book will go to legal fees for the several lawsuits the Exners have going at the moment, a couple of libel suits and one suing the FBI for her files.

For Exner this whole reemergence and the attendant publicity has been a shock because of the last 16 years when she kept her silence. "Sixteen years is a long time to keep a secret," she says.

She explains herself during her Kennedy-Giancana years simply, this way: "In those years I was lost. I know what I have now is what I was add 15 EXNER - Style Fri. Cap - x14.9 looking for. I never did adjust to any other kind of life. I finally just stopped going out. I just stayed home for years with my parents until first my mother, then my father, died of cancer. Then I withdrew completely."

One wonders, after all her years of seclusion and anonymity, whether doing this book and having to go through with the publicity all over again is worth it.

"I'm dealing with my gut reaction," she says. "I really truly feel I've been wronged. I'm doing the book tour because of opposition. I want people to see what I'm like."

She suddenly seems to be injected with a strength and her whole posture changes for just a moment before she goes back into her state of repose.

"John F. Kennedy is a source of great hardship for me," she says. "Sam Giancana is a source of great hardship for me. I'm very sorry this whole thing came up. I would rather have gone on with my life, with my husband, privately, the way we were. But God Almighty, now that it's come up I will fight it to the grave."