Suzan Mubarak lived a double life -- as a quiet, private, hard-working graduate student, and as the photographed, talked-about, spotlighted wife of the Egyptian president.

Yesterday at American University, Mubarak, 42, allowed a rare glimpse into that delicate balance. She spoke softly in her excellent English to the crowd of about 150 on education. And then, looking small, she stood without ceremony or obtrusive security guards to talk earnestly with and to shake the hands of the students (including some 25 Egyptians) and faculty who came to do her honor.

In contrast to the outspoken Jihan Sadat, widow of President Anwar Sadat, Suzan Mubarak seems quiet, unassuming, almost retiring. She is here with her husband, who has been meeting with President Reagan about Lebanon and as a part of his effort to enhance Egypt's position in the Arab world. Mubarak said she felt at home in the academic atmosphere of AU because of her studies at the American University of Cairo, from which she recently graduated with a master's degree in sociology with an emphasis on urban education.

"For me to be a student was very different. I couldn't join in the student activities," she said, "because of my duties for my husband. I was rushed to my classes and then rushed away after them, on to official engagements. When I first went back to school, it was not so difficult. But when my husband became vice president, the demands on my time became very great. I don't think I could have finished my degree after he became president if I had not already done all the class work and research for my master's thesis."

Even so, Mubarak, who graduated from high school at 16, became an honor student when in her late 20s she went on for higher degrees.

"It was my husband's idea for me to go back to school 10 years after we were married, after our children were born," she said. "If he had not supported me in this project, I could not have done it. My two sons, on the other hand, never have understood why I wanted to study. They said, 'Mother, we'll be so glad to be out of school, why do you want to go back?' "

The elder son, Ala, is 22, also a sociology major, and graduated last year from the Cairo AU. The younger son, Gamal, 20, is expected to graduate this year.

Suzan Sabet, the daughter of a Welsh mother and an Egyptian father, in 1958 married Hosni Mubarak, then an air force captain. Their life changed drastically when the captain met Anwar Sadat in the early '50s at Al-Arish military base. Sadat was impressed enough with Mubarak to make a note of his name. Both came from the Nile delta region.

Hosni Mubarak studied for a year in the Soviet Union and in 1967 he became commander of the Air Force Academy, moving up quickly to chief of staff of the air force, deputy minister of war and planner of the assault on Israel's Bar-Lev Line, and eventually vice president in 1975.

During these years, Suzan Mubarak reared their two sons and took care of the details of their life. Her husband had almost no free time. It was at this time that he urged her to go back to school. About 1968, while he was still with the air force, she took a course in early childhood education.

"It was then," she said in her speech at AU, "that one of my professors accused us, saying, 'You people don't really know what conditions the poor children live under.'

"I thought about that remark many times," she said. "And so, when I did my thesis for my master's degree, I studied ways to upgrade 12 schools with 12,000 students in a poor section of Cairo."

Mubarak said that in 1952, the illiteracy rate was 80 percent. "Only 40 percent of school-age children attended classes. Colonial powers had denied education to all but a small elite class as a way of keeping the people in subjugation. When we achieved independence, we had to choose quantitative education, at the price often of quality. The demand for education was so great. The classrooms were so overcrowded.

"Now we have 8 million children in school, 5 million of them 6 to 12 years old. About 75 percent of this age group are now in school, and we hope by 1985 to have the entire school-age population attending classes."

During the reception, between shaking hands and posing for pictures with students and teachers, Mubarak said that, in her opinion, Egyptian women had no problem with equal rights. "But equal pay, that is the difficulty."

So what will she do with her MA?

"No, of course, as the president's wife, I have no time to teach. Though I would like to. I am an advocate for education with my husband." She is president of the project intent on upgrading the schools.

AU President Richard Berendzen presented her with a presidential citation honoring her for her efforts to "better the education and the life of the people of your nation."

Thursday, Suzan Mubarak had tea with Smithsonian Secretary S. Dillon Ripley in his parlor in the Castle. She toured the Near Eastern collections of the Freer Gallery with director Tom Lawton, who said she was interested and knowledgable about the objects.

Yesterday she attended a lunch given by Lorraine Percy, the wife of Sen. Charles Percy, chairman of the Senate Foreign Relations Committee. After a visit to New York today, the Mubaraks will make the first visit by an Egyptian head of state to Canada.