Besides family issues, Michelle has also talked about her role as US First Lady and why she won't seek elective office.
"Just curious, just wondering if somebody rubbed you the wrong way", Kimmel said.
These are among the revelations that Mrs Obama, whose husband has Kenyan roots, makes in her new book, Becoming, which hit the bookstores on Tuesday.
In a clip from the show (above), Michelle tells Kimmel that during her eight years in the White House she had to be very careful about what she said. And my staff was calling me, everybody was celebrating, people were crying, and I thought, I want to be in that. The tough, smart, strong, classy and eloquent Michelle Obama is peeled away to reveal a simple wife and mother who like any other women in society was enduring battles that only she could understand. Instead, the Obamas' eldest daughter Malia made a decision to join.
A passage in the book reads, "If I were to start a file on things nobody tells you about until you're right in the thick of them, it is miscarriages". To her relationship with her kids, "I'm not sure which one is Sasha and which one's Malia". "I'd ill-advisedly bought new white sneakers to wear on the trip, and within a day, after all the pushing we did, they'd turned reddish brown, stained with the cinnamon-hued dust of Nairobi", she writes.
"You see how much we miss you?" But we just took it in. "Laura, sorry. Send me the bill", she added.
She read two books to the 4-year-olds assembled: "The Gruffalo" by Julia Donaldson and Alex Scheffler, and "Llama Llama Red Pajama" by Anna Dewdney.