Michelle Obama's book earns a 'thumbs-up' from her daughters

"The book American Grown is everything I would have imagined,” the first lady said at the book-signing event. “I wanted the book to be beautiful and I think that the pictures are absolutely beautiful. I could tell because when Malia and Sasha picked it up — you know, it's 'Mom, it's like, oh, your book, how nice.' They actually got pulled in by the pictures. They couldn’t put it down and they started looking through it and then they started reading it. And eventually I got actually a thumbs up.”

Obama said at the event that it was "my first book and my very first and probably only book signing."

The book signing itself, hosted at a Barnes & Noble in Washington, D.C., was difficult to pull off due to security requirements. Those hoping to get a signed book were required to submit their social security number and photo ID as well as pre-purchase a copy of the book on location the Friday before the event and leave it at the store. Those efforts though did not guarantee the book would actually be signed, according to Eddie Gehman Kohan at the blog Obama Foodorama.

The first lady's book American Grown: The Story of the White House Kitchen Garden and Gardens Across America, released May 29, is a large picture book that includes stories about the White House garden project and garden-oriented recipes.

All proceeds from the book go to the National Park Foundation. The first lady declined to accept an advance fee for the book.