"When we look at our own history we know that we, of course, have not done everything right," she told NBC television's Today Show programme on Monday.
"We started off with a perfect document that didn't abolish slavery until almost a hundred years later," she said, referring to the US Constitution. "Women didn't get the right to vote until almost a hundred years ago in the United States."
"As we try to promote democracy and human rights and women's rights around the world, we have to look at ourselves as well and to make sure that we're living what we're saying," she said.
Arrival in Egypt
The first lady arrived in Egypt on Monday for the latest stage of a Middle East tour in which she encountered anti-American protests in Israel.
Upon her arrival in Egypt, the wife of US President George Bush immediately went to the presidential palace to pay a courtesy visit to Suzanne Mubarak, the wife of Egyptian President Hosni Mubarak.
She was due to tour a primary school southwest of Cairo on Monday and end her visit with a trip to the Pyramids.
"These are very, very moving and emotional and important world sights"
US first lady
"These are very, very moving and emotional and important world sights. We want there to be a peace here in the Middle East, so that Christians and Muslims and Jews can all be here and can all come to these very important sights in peace with each other," she told NBC.
Bush said she had not been surprised by the protests during her visit on Sunday to Jewish and Muslim holy places in Jerusalem's Old City.
"I wouldn't say I was really surprised. These are places of very high emotions," she said.
"Later I met with Palestinian women. First I'd met with some Israeli women. Both groups said that what they want is peace. They want to be able to live there in peace and they want the United States to be a part of the peace process," she said.