She leans forward, looks you straight in the eye and announces, "This may sound presumptuous, but no one in the United States knows more about day care than Grace Mitchell."

Mitchell's son is criminal lawyer F. Lee Bailey, who's never been known as a retiring sort. Neither is his mother. At 70, she's taken on what she calls My mission in life" -- helping create quality day -- care programs and encouraging parents to track down the best.

"My dream is equal opportunity for all children," writes Mitchell in her new "The Day Care Book: A Guide for Working Parents to Help Them Find the Best Possible Day Care for Their Children" [Stein and Day, 239 pgs., $10].

"I want every child whose parents use day care to be assured of a pleasant, safe environment; of the physical care that will help his body to grow strong, and the loving care and mental stimulation that will develop his I AM and I CAN. . ."

Stressing the need to "put pressure on the budget -- makers," she says, "we, the people must recognize our responsibility to our nation's children."

Mitchell founded in 1933 -- as the first of 40 centers she has helped start -- the Green Acres Day School, Waltham, Mass., operated at first in her own home. "Lee was 5 weeks old and in a basket. I charged $1 a week, and I was lucky if I got that dollar," she said during a stop in Washington.

She also was a government adviser of facilities for the children of World War II industries workers. Now educational director for Living and Learning Centers, Inc., in Waltham, which operates 25 day -- care centers, Mitchell earned her master's in education at Harvard when she was 53 and her Ph.D last year from Antioch's Union Graduate School.

The book is a result of her dissertation, for which she is visited and evaluated more than 150 child-care centers in 22 states, ranging from a 24-hour Youth Hotel on the Las Vegas strip to facilities on three Indian reservations.

Some of her most negative reactions were to a slick and high-priced, but cold and regimented urban center. ["Many parents equate high cost with quality."] Some of her most positive to a moderately-priced nursery school run by a young couple in an old house. ["The staff did not have to pretend to be interested; they were obviously having as much fun as the children."]

"I rely heavily on my senses," Mitchell says, "on what I can see, hear, smell, touch and taste, and most of all on my sixth sense -- intuition."

Her book could make any parent feel guilty if they've grabbed the first day-care center someone said was all right. She'd have you go back again and again, being aware of such basic things -- to mention a few -- as:

NOISE -- "if it was unnaturally quiet, I was concerned. I was listening for the pleasant hum of purposeful activity. . . good noise."

SMELL -- "Moldy, damp odors are prevasive ad hard to conceal with spray. A clean, well-kept center has its own special smell, a combination of soap and water, a whiff of cologne as a teacher passes by and the smell of good food cooking."

TOUCH -- "I looked for people touching each other: An adult with his arm around a child, a teacher administering a comforting pat to passing children, who in turn responded with affectionate hugs or stroking. . . I was looking for comfortable laps -- frequently occupied."

EQUIPMENT -- "If I could select only two pieces of equipment I would choose blocks for the inside and a sandbox for the playground."

SURFACES -- "Indoors and out. Soft cushions, shaggy carpets smooth tiles. Rough cement, fine sand, prickly pine needles -- a variety of textures to enrich a child's experiences."

LOOKS -- "Children's faces reflect contentment. Look for the expression of joy. The caregivers' faces tell much about the overall tone of the center."

STAFF -- "The right 'mix' . . . where everything revolves around the ideas of self-concept and self-competence . . . for both teachers and children."

ETHNIC AND SEXIST CONCERNS - "Are there black and white dolls? Books about children who may look different from those in the center? Do the story books always show female nurses and male doctors? A father who goes to work and a mother wearing an apron?"

YOUR SIXTH SENSE -- "Each child's background prepares him for something different. Would a large center with many activities be stimulating -- or overwhelming? Would a single room in someone's home be cozy -- or confining?"

"The day-care center is a second home for the child, "says Mitchell. "He may spend more of his waking hours in it than in the dwelling he calls home." But she admits that parents may have to compromise. "Nowhere are you likely to find day care that has everything you would like."

And now for some of her dreams, the fantasies Mitchell says keep her awake at night:

MONEY -- "I see a pot of gold at the end of the rainbow filled with tax dollars which our national budget-makers have apportioned for child care.The amount will depend on the citizens of our country, and the pressure they put on. . . I am not naive enough to suggest that quality day care would be a sure-fire panacea. . .but I do know that when a human being can feel good about himself as a person and can achieve some measure of competency, he is less apt to be filled with the anger and frustration which triggers antisocial behavior."

Mitchell, she recounted, once said about her son, Lee Bailey one of three children: "'This child of mine could be a criminal. He could go either way.' He had the kind of mind that had to explode in some way. He could not be forced into a mold." She searched for "unregimented" schools, and is "delighted that he became a criminal lawyer instead."

LICENSING PROCEDURES -- Establishment of uniform regulations between the states.

CHILD-CARE COURSES -- Offered on educational television, for credit.

TRAVELING TEAMS -- Professionals in early-childhood education evaluating day-care centers and setting up resource centers for books, record, toys, and audio-visual materials and equipment.

SUBSIDIZATION -- From both the government and private industry, with fees on a sliding scale, "to put an end to socioeconimic, ethnic or cultural segregation in child care."

Mitchell, who was divorced from Bailey's father in 1941 and is now married to a retired high-school administrator, admits readily that getting a publisher for her book might not have been so easy were it not for her famous son.

"But as I said to Lee, 'Any time I can ride on your coattials, and it will help daycare, I'll do it."' CAPTION: Picture, Grace Mitchell: "I rely heavily on my senses . . . and most of all on my sixth sense -- intuition." By Doug Chevalier -- The Washington Post