Michelle Obama Pictures

First Lady Michelle Obama participates in a "Let’s Move!" and NHL partnership event with Chicago Blackhawks and Washington Capitals players on the South Lawn of the White House, March 11, 2011. (Official White House Photo by Samantha Appleton)

First Lady Michelle Obama greets guests at the National League of Cities Conference in Washington, D.C., March 15, 2011. (Official White House Photo by Samantha Appleton)

President Barack Obama and First Lady Michelle Obama talk with Irish Prime Minister Enda Kenny and his wife, Fionnuala Kenny, in the Green Room of the White House before a St. Patrick’s Day reception, March 17, 2011. (Official White House Photo by Pete Souza)

President Barack Obama walks with Brazilian President Dilma Rousseff following the arrival of First Lady Michelle Obama, and daughters Sasha and Malia, at the Palacio do Alvorada in Brasilia, Brazil, March 19, 2011. Foreign Minister Antonio Patriota, right, shakes hands with Malia. (Official White House Photo by Pete Souza)

President Barack Obama, First Lady Michelle Obama, and daughters Sasha and Malia, tour the Christ the Redeemer statue in Rio de Janeiro, Brazil, March 20, 2011. (Official White House Photo by Pete Souza)

President Barack Obama and First Lady Michelle Obama gather with President Sebastián Piñera of Chile, wife Cecilia Morel, and their family for a photograph during a dinner at La Moneda Palace in Santiago, Chile, March 21, 2011. (Official White House Photo by Pete Souza)

Chilean First Lady Cecilia Morel, right, talks with First Lady Michelle Obama and daughters Sasha and Malia during a cultural event at the Museo Interactivo Mirador in Santiago, Chile, March 21, 2010. (Official White House Photo by Samantha Appleton)

President Barack Obama and First Lady Michelle Obama greet children during the arrival ceremony at Comalapa International Airport in San Salvador, El Salvador, March 22, 2011. (Official White House Photo by Pete Souza)

President Barack Obama and First Lady Michelle Obama toast during an official dinner hosted by Salvadoran President Mauricio Funes at the National Palace in San Salvador, El Salvador, March 22, 2011. (Official White House Photo by Pete Souza)

First Lady Michelle Obama helps paint a mural during a community service project at the Superate Youth Center and Health Clinic in San Salvador, El Salvador, March 22, 2011. (Official White House Photo by Samantha Appleton)