Maybe that teen-ager stretched out in your living room watching reruns of "The Jetsons" hasn't looked so bad lately; after all, the kid did grunt a greeting in your direction last week and yesterday managed to put something in the dishwasher for the first time in four years. Well, forget it. Meet Lori Jo Smith, Miss Junior Miss 1986, recently graduated from Oakton High School in suburban Virginia.

Lori Jo Smith is a member of the National Honor Society, was president of the student council, and a member of the Episcopal Young Churchmen. She doesn't wear plastic rats in her ear and you can see her face, which is framed by a halo of curly blond hair ("the color is natural but the curl is not"). She drinks water at parties, and when someone asks her if she wants a smoke, a toke or a snort, she just says "no."

She got into all six of the colleges she applied to, and chose Princeton.

She says nice things about her parents.

She doesn't fight with her mother about clothes, because she likes the "classic" blazers and skirts Vivienne Smith favors. Her idea of something wild is a fuchsia blouse.

So maybe she didn't make her bed every day last year when she was student body president and rushing off at 6 a.m. to prepare for meetings at school. But her room is not a mess. "She prioritizes," said her mother.

"I'm very disciplined," said Lori Jo. "If I have a goal I go for it."

Yesterday, Sen. Paul Trible (R-Va.) hosted a reception for Lori Jo at the Capitol, because she is the first girl from Virginia to win the national title. Trible has known about the contest for a long time, because his wife Rosemary was America's Junior Miss in 1967.

"It was tremendous exposure for me," said Rosemary Trible yesterday. "It really challenged me." Her $10,000 scholarship helped pay her way at Sweet Briar College (she graduated from the University of Texas). She gave up a television talk show in Richmond when her husband first ran for Congress 11 years ago, and recently left a job as executive vice president of an international interior design firm. She is now waiting to see "what the Lord wants me to do," in the area of working with the hungry and homeless.

"They the Junior Miss judges are looking for a vitality of life, a vivaciousness and eagerness to pursue their goals," said Rosemary Trible.

"It is not a beauty contest," cautioned Carol McLeod, 1973 Junior Miss, who is Lori Jo's "companion" for official duties. (The former winners and competitors are called "has beens.") But she did admit that someone who was 200 pounds would probably not make it.

As it happens, all the Junior Misses since the program began in 1958 have been pretty in an All-American way, bright-eyed and pert like daisies in a chain, like Diane Sawyer, Junior Miss 1963. All of them have been white, and Christian, although there have been some competitors of different races and religions.

But if the word "teen-ager" has come to be synonymous with wet towels on the floor, or the more serious statistics about drugs, drinking, sex and suicide, here is Lori Jo Smith to represent another group. She wouldn't even feel comfortable posing in a bathing suit.

"I always wonder when I see actresses in bathing suits or in their nothings, what would their daddies think?" she said.

Her daddy, Dick Smith, retired from the Army after 24 years and now works for Textron Inc. Her brother Rob will be a senior at Princeton this year. Vivienne Smith is a counselor at Bren Mar elementary school in Fairfax County. And they all live on Apple Blossom Court.

"Junior Miss stands for everything I believe in," said Lori Jo, who was also homecoming queen and until last fall had a part-time job in a law firm, and who has the highest award in Girl Scouting.

Her curfew is midnight and she doesn't whine about it.

As student body president she reinstituted sock hops. "I want to show kids there is an alternative to an artificial high," she said. "I don't think I was popular in high school, but I was respected, and that's more important to me." Her English teacher wrote in a recommendation, "I have seen Lori, in my opinion, as perhaps the best student government president we have had at this school since I'm here (6 years)." A few weeks before the national contest, Lori Jo sprained her back in an auto accident (not her fault), which meant her jazz dance routine was executed in considerable pain. "It was a challenge," she said. "I gave the burden to God." But she won anyway, and afterward told a news conference in Mobile, Ala., where the contest is held, "I just have a warm happy bubble inside."

Her $25,000 scholarship, plus the other scholarships she has won, will pay for the first two years at Princeton, which runs about $18,000 a year.

But hey, she's not perfect. "I love to eat," she giggled, and she admitted she didn't have as much time to read "as I might like." She cited "The Once and Future King" and "Les Mise'rables" as her favorite books. Her strongest trait, she said, is her ability to concentrate. This spring, when she was involved in too many activities, she drew herself a schedule on a piece of graph paper and "just stuck to it."

She hopes for a career as a manager in an international firm, but plans to take off a few years when she has children if her finances permit. She admits to being ambitious.

"My Mom has been called a velvet hammer," she said. "And I like to think of myself that way."