Jane Curtin is sitting in her suite at the Grand Hyatt Hotel trying to relax, but it's not so easy. It's been a tough week. She woke at 6:30 to do a television interview -- live -- for an hour. She had gone to bed late because of last night's reception, which followed yesterday's congressional luncheon, which followed yesterday's congressional visit, which followed the receptions and interviews in Boston the day before. Tomorrow there's New York and more of the same. It seems endless: Stand up, shake hands, sit down, smile, say the right thing. Easy for a politician. Difficult for a shy actress with no script. "It's like being back in improvisational theater," she says.

Curtin, known as Allie Lowell on the CBS comedy series "Kate & Allie" and in real life a married mother of one, was in Washington last week as the chairperson for the 1987 National UNICEF Day, observed on Halloween. She emerged from her cocoon of privacy to campaign publicly on behalf of UNICEF, which raises funds for needy children in 119 developing nations worldwide. "When I got the letter asking me to become part of UNICEF, I hadn't heard about the organization for a long time," she says. "It's the kind of thing you can't say no to."

The handsome, gracious actress, who made her reputation as an original cast member of "Saturday Night Live" and won the 1984 and 1985 Emmy Awards for Best Leading Actress in a Comedy for "Kate & Allie," takes her position as UNICEF chairperson seriously, having visited with volunteers in Boston, New York and the District. "It's not a glitzy organization," she says. "It's not a glamorous group. It's just a group of very hard-working people."

Curtin is no stranger to hard work. Born and raised in Cambridge, Mass., the youngest daughter of an insurance executive, she studied drama at Boston's Northeastern University and worked in improvisational theater for four years, touring nationally with a number of companies before landing a role on "Saturday Night Live" in an open audition. Her five-year run, in which she shared the spotlight with some of today's top comedians, made her a household name. One of her most famous colleagues was the late John Belushi.

"He suffered from the Diana Barrymore syndrome," she says of Belushi's rise to stardom, which ended with his death by heroin and cocaine overdose in 1982. "Too much too soon. You watch something like that happen, and as much as you'd like to help, you were powerless to stop it. His idols {such as Lenny Bruce} all made a strong impact and died. These were people he admired. You could see it coming but you couldn't stop it."

Which was one reason the actress always avoided publicity. "It changes your life," she says. "It's very precarious, the adulation of the press. You see yourself on the cover of magazines and it damages you. I've never been on the cover of a magazine and I don't know if I want to be -- then you have to deal with your face. You're dealing with your persona and how it is manufactured. You can understand how people get face lifts, because you have videotapes and reruns to haunt you. In theater, you can grow old gracefully."

Not that growing old is something she's losing sleep over. Just turned 40 ("when you're 40 you make more noise getting out of a chair"), she is the wife of producer Patrick Lynch and the mother of a 4-year-old. The family lives in a 50-year-old house in Sharon, Conn., where Curtin the television mom attends to real-life mom duties just like everyone else. "I love it," she says of motherhood. "I don't know what I did with my time before."

Being a mother is another reason the UNICEF gig strikes close to home. "It's very difficult to turn down starving children," she says.

That's something Capital Centre owner Abe Pollin, chairman of the Washington UNICEF council, knows quite well. He first read an account of 40,000 children starving in Africa and was so shocked by the numbers that he telephoned the reporter to see if they were accurate. When he discovered they were, he took over the reins of the local UNICEF council, raising $250,000 and traveling to northeastern Uganda personally to see that the assistance was reaching those who needed it.

"The beauty of our program is that every penny raised in Washington goes directly to the projects there," Pollin says.

Pollin has transformed Washington's UNICEF council into the "leading volunteer group we have in the country," according to Lawrence E. Bruce Jr., president of the U.S. Committee for UNICEF. Pollin says his goal for next year is to raise an additional $150,000 to feed starving children in Niger. "It's not a job," he says of his role. "It's something I feel privileged to do."

It's a privilege Curtin is happy to share with him. In her hotel suite, she reaches for another smoke and stands up to welcome yet another reporter here for yet another interview. For the actress, it means one more hour of ad-libbing. In the end it's a small price to pay, says Curtin. "I went to a reception in Cambridge and there were all UNICEF volunteers there," she says. "They were an interesting group of people -- 60-year-olds with grandchildren, college students. It was a cross section of the population. Because of the nature of my job, I have the availability of a platform I haven't used.

"It's a hard decision, but I'm glad I used it. The cause is worth it."