She sits close to you, leaning forward a little, peering over her glasses somewhat like a schoolteacher about to scold. But the mischief in her gray eyes tells you that Maggie Kuhn, in Washington to lead her Gray Panthers during this week's White House Conference on Aging, is having a lot of fun in her work.

She is 76, white-haired, slightly built. But she is surprisingly vibrant and talks decisively. "It's tough hardball we're playing out there, but we've got to keep it up," she says firmly.

Yesterday was a typically busy day for her: several meetings concerned with problems of the elderly, picketing in front of the White House, an interview, a press conference. The press conference was packed into a tiny room at the Shoreham. Flashing cameras. Hot bright lights. Eager questions from all directions. Nothing ruffled Kuhn, who stood on a box to reach the thicket of microphones.

When it ended, she thanked everyone, threw a purple and blue striped shawl across her shoulders for protection in the drafty corridor and headed off carrying a sheaf of papers. She accepted a compliment about her shawl, saying, "It's handmade. I bought it in New Mexico, and I met the Indian woman who made it." Then she paused in an empty meeting room to discuss her causes, past and present. The Gray Panthers, the group she founded andwhich includes all ages, are dedicated to demanding that America give its older citizens an active role in society.

"I was almost arrested just 10 years ago at the 1971 White House Conference on Aging," she recalled. "We gathered at the New York Avenue Presbyterian Church, that was President Lincoln's church, you know. Well, we managed to gather about 1,000 blacks and Hispanics and after the hearing 75 of us went to the White House to take our message and to call on the host.

"Then the police came on their horses and rode right into us, you know. That was frightening, those enormous beasts and those hard shoes, a blow could kill you.

"I was knocked down but I got up and left."

Maggie Kuhn has spent most of her life "in-fighting," has been knocked down at times, though not physically except that once, but has always gotten right back up and into the cause.

She joined the Jeannette Rankin Brigade years ago, and she worked long and hard in the civil rights movement, the women's movement and the anti-Vietnam war movement.

Her campaign for the aged began back in 1970 when, at 65, she was forced to retire from her job with the Presbyterian church missions in Philadelphia.

"I felt suddenly shocked and wounded, then angry, at having to be sent out to pasture," she said. "Then I figured there must be thousands of old people just like me, so I decided it was time to fight back."

Born in Buffalo, Kuhn grew up in Cleveland, Memphis and Louisville, and graduated from the College for Women in Cleveland in 1927.

"I was very sheltered as a child," she said. "I really never grew out of the adolescent revolt. My father was a very authoritarian person." Growing pensive, she said, "That's what I still seem to be doing, revolting."

She works as hard now as she ever did, and gets no money for it. Her retirement income comes from Social Security and a pension from the YWCA, where she worked for 20 years. "I put in a long day, seven days, but I don't get up early," she said. "I like to sleep until about 8:30 or 9. I'm a night person, I like the quiet of nights and stay awake until about 2 a.m." In a conspiratorial tone she adds, "My best hours are from about midnight until 2. It's very nice and quiet then.

"I read a lot. I have always enjoyed The New Yorker magazine, for years it has been my favorite. Other magazines are Mother Jones, In These Times and, of course, the Gray Panther Network. I do enjoy Simone de Beauvoir, and have been reading her lately."

She travels about 100,000 miles a year. "There is a lot of excitement in travel. I enjoy meeting with the different Panther groups, and learn how they approach the problem of aging, and I enjoy speaking before people concerned with age."

The arthritis in her hands and knees slows her down a bit, but it doesn't stop her. "My recipe is just to live with it," she said.

Her home in Philadelphia is an "integrated" household, she said. It has both young and old living there.

"It is wonderful, it is very good for others to know how the old feel about life and good for the old to keep up with the young ideas. We are encouraging more homes like this throughout the country. We have a big food co-op. Everyone puts in their time working there. It helps keep the high cost of living down.

"My diet now is more vegetarian, and we have a big community garden. I would like to see older people in communities start co-ops, set a place aside for a big garden to grow their own vegetables. "And a mini-library. Wouldn't that be wonderful, food for the mind."

Kuhn also is a member of the committee on aging for the Philadelphia Presbytery, and has recently started a monthly column for the Philadelphia Bulletin.

"They wanted me to write a column a week, but I said, 'Goodness no,' so I do one a month and had my first one printed. I called it 'Upsetting the Jelly Bean.' "

Her second column, she said, will be prompted by an old federal government study on the effects on society of a nuclear attack. The report indicated that older people were less vulnerable to radiation. "It was suggested that people could stay in a shelter for a minimum of two years," she said. "Then, the old people would be made to go outside and work to test the area, they being expendable."

Kuhn has a saying: "At our age, we have to live for the future." And so, among her goals, she seeks jobs for women of all ages, blacks, Hispanics, teen-agers, students.

"We have a lot to do in the world," she said. "Next year we are going to have a world assembly in Vienna."

Kuhn then was summoned to yet another conference meeting, and you felt from meetingthis deceptively frail-looking woman that the Gray Panthers have the right person leading them. She said goodbye and departed quickly, several younger aides striding to keep up.