Children sing as Michelle Obama, unseen, visits the Hector Pieterson Memorial in Soweto, South Africa Wednesday June 22, 2011. (AP Photo/Themba Hadebe)

First lady Michelle Obama reacts to a student’s question at the University of Cape Town in Cape Town, South Africa, Thursday, June 23, 2011. (AP Photo/Charles Dharapak, Pool)

Student Mikhail Hendricks, 16, left, embraces first lady Michelle Obama after she answered students’ questions at the University of Cape Town in Cape Town, South Africa, Thursday, June 23, 2011. (AP Photo/Charles Dharapak, Pool)

Michelle Obama listens to Ahmed Kathrada, former political prisoner on Robben Island and anti-apartheid figure, as she visits the District Six museum, in Cape Town, South Africa, Thursday, June 23, 2011. (AP Photo/Charles Dharapak, Pool)

Michelle Obama plants spinach as she gardens during a community service project at Vhuthilo Community Center in Soweto township, Johannesburg, South Africa, Wednesday, June 22, 2011. (AP Photo/Charles Dharapak, Pool)

Michelle Obama holds up a carrot she just harvested as she gardens at a community service project at Vhuthilo Community Center in Soweto township, Johannesburg, South Africa, Wednesday, June 22, 2011. (AP Photo/Charles Dharapak, Pool)

Michelle Obama walks Sibongile Mazibuko, director, of the Vhuthilo Community Center in Soweto township, Johannesburg, South Africa, Wednesday, June 22, 2011. (AP Photo/Charles Dharapak, Pool)

Michelle Obama stands with Karen Dudley, right, at her restaurant “The Kitchen” as she makes an unscheduled stop for lunch in Cape Town, South Africa, Thursday, June 23, 2011. Also pictured, left to right, daughters Malia and Sasha Obama, niece Leslie Robinson, nephew Avery Robinson. (AP Photo/Charles Dharapak, Pool)

Michelle Obama and her mother Marian Robinson, right, listens to Bonita Bennett, director, as they visit the District Six museum, in Cape Town, South Africa, Thursday, June 23, 2011. (AP Photo/Charles Dharapak, Pool)

Michelle Obama is seen in silhouette as she speaks at Regina Mundi Church and addresses the Young African Women Leaders Forum in a Soweto township, Johannesburg, South Africa, Wednesday, June 22, 2011. (AP Photo/Charles Dharapak, Pool)

Audience members listen as Michelle Obama speaks at Regina Mundi Church as she addresses the Young African Women Leaders Forum in Soweto township, Johannesburg, South Africa, Wednesday, June 22, 2011. (AP Photo/Charles Dharapak, Pool)

Michelle Obama, right, pays her respects with Antoinette Sithole, left, the sister of the late Hector Pieterson, after laying wreath at the memorial in Soweto, South Africa Wednesday June 22, 2011. (AP Photo/Themba Hadebe)

Michelle Obama, right, stands with Antoinette Sithole, left, after laying a wreath at the Hector Pieterson Memorial in Soweto, South Africa Wednesday June 22, 2011. (AP Photo/Themba Hadebe)

Michelle Obama hugs youth after participating in a community service project at Vhuthilo Community Center in Soweto township, Johannesburg, South Africa, Wednesday, June 22, 2011. (AP Photo/Charles Dharapak, Pool)

Michelle Obama, center, kicks a soccer ball as she and former Anglican Archbishop Desmond Tutu, unseen,visit children at the Cape Town Soccer Stadium, Cape Town, South Africa, Thursday, June 23, 2011. (AP Photo/Schalk van Zuydam)

Michelle Obama, left, reacts as former Anglican Archbishop Desmond Tutu, right, speaks to children at the Cape Town Soccer Stadium in Cape Town, South Africa, Thursday, June 23, 2011. (AP Photo/Schalk van Zuydam)

First lady Michelle Obama stands with Archbishop Desmond Tutu as they watch youths play games to raise awareness for HIV prevention at Cape Town Stadium in Cape Town, South Africa, Thursday, June 23, 2011. (AP Photo/Charles Dharapak, Pool)

Michelle Obama listens to Ahmed Kathrada, left, former political prisoner on Robben Island and anti-apartheid figure, as she visits the District Six museum, in Cape Town, South Africa, Thursday, June 23, 2011. (AP Photo/Charles Dharapak, Pool)