CAIRO -- "Being close as a family is part of our tradition," says Egypt's first lady. "It would be unheard of for us, in spite of our responsibilities, not to put our family life first. Definitely!"

Susan Mubarak, who arrives with her husband today on his first state visit to the United States, says she and her husband share that traditional family closeness with two sons in their early twenties who live with them. "When the president comes back at night, we ask him what he has done that day, and he says I met this person or that. Like any other family, we discuss the problems of the day."

In an era when the question of a wife's influence on a head of state has become an issue in many countries, she is forthright about her role. "I think all families discuss politics," she said. "The world is so small. You put on the TV and you see problems all over the world. Unfortunately, all you see is problems, so you just can't help but discuss it, even more so when the father is the president and the problems fall into your living room.

"The boys always have a lot of questions to ask their father and they hear my opinion," she said. "They may not agree with what they hear, but they hear it."

On Oct. 13, 1981, after the assassination of Anwar Sadat and the inauguration of Hosni Mubarak as his successor, Susan Mubarak became the first lady of Egypt, replacing the controversial and highly visible Jehan Sadat. "Overnight you become first lady and you wake up to a question I'm sure most first ladies will agree with me on. You just sit back and ask yourself, 'Now what is expected of me? What am I supposed to do?' "

All first ladies need an identity, and Susan Mubarak's grew out of her fondness for children. "Everyone has their own field of interest apart from the obligations of all first ladies," she said, during an interview at her home the evening before her departure. Her pet cause, she said, is books for children -- a sparse field in Egypt, a country where more than 60 percent of the adults can't read, and with few books written in Arabic for Egyptian children.

The cause began, she says, when she went back to the university after 10 years of marriage. She obtained a bachelor's degree in political science with a minor in sociology, then a master's degree in the sociology of education.

"The sociology of education deals with the different problems the child has to face just to go through an education, such as the community, family, environment and the system," Mubarak said. "This is where my interest started in the education of children.

"The major problem we are facing in Egypt concerning children today is changing the educational system, providing more classrooms to reduce the student-teacher ratio of 70 to 1," she said. "The quality of education in terms of curriculum has not changed for many years."

To help in that struggle, Mubarak has worked to establish a "documentation" center for children's literature. Scheduled to open early next month, it will serve as a research center for writers, illustrators and anyone interested in working with or writing about children. In the United States, she said, she will be meeting with American publishers. "I need their help," she said. "We need variety in children's books, and at the same time, we'll discuss the possibility of translation and printing."

For the past three years, she has also been involved in the creation of a science museum for children, which will be completed by the end of this year. "To have a museum specially for children is something I am very proud of," she said. "We have many museums in Egypt but none of them offers programs directed towards children. The concept of a children's museum is new in the Arab world."

In all her children's projects, she said, "a group of us are working together, and none of us is a professional in this field. We are all learning, traveling, teaching ourselves and each other as we go along."

Mubarak is also involved with gifted and handicapped children and will be meeting in Washington with a group that will brief her on programs for such children. "This is an area we have not looked into yet because there are so many problems just with ordinary children," she said.

Mubarak said that because of its traditionally close families, Egypt has been largely spared many of the major social problems -- like drug abuse -- plaguing the West, but drug use has started to make inroads among Egyptian young people.

As the first first lady since Raisa Gorbachev to visit the White House, she plans to use the antidrug cause as a talking point with Nancy Reagan. "I am going to be seeing Mrs. Reagan and visiting one of the rehabilitation centers" in the United States, she said, because "I don't think we should just sit back and wait until it becomes a huge problem. I think we should start dealing with it immediately.

"We do not have rehabilitation centers for drug users," Mubarak continued. "I hope that when I visit the center I will be able to get some ideas." She said she is sorry she was not able to attend the first ladies' conference organized by Mrs. Reagan two years ago to address the drug problem, "but I am sure she will be able to give me all the papers and introduce me to someone who can tell us how we can start to deal with this problem."

Unlike her predecessor Jehan Sadat, Mubarak says she is not especially interested in writing her autobiography. But she is interested in compiling her experiences working with children: "things I have achieved to make it easier for others who come after me -- not just first ladies but anybody who wants to establish a children's library."