From a thematic point of view, it makes sense that the girl would express some level of hope in being able to return back to her village.  If the girl did not articulate something that is reflective of a desire to view her home again or return to it, then I think that the tone of the short story, and perhaps of Gordimer herself, is an extremely bleak one.  The girl and her family only flee their village because the conditions in it force them to do so.  They do not hold disdain for their home in Mozambique, nor do they hold a sense of political rejection of it.  They only leave because the conditions are so dangerous, their home is no longer capable of habitation.  In expressing a desire to return to it at some point, Gordimer brings some level of hope to the political situation that has a hold on many parts of Africa and the world.  Consider what Jeanne Colleran wrote about this idea:

While much of the collection, with the ‘obsessive image of recent South African history, the dead . . . children [that] haunt the collection,’’ portrays the dire legacy of apartheid, ‘The Ultimate Safari,’ written through the eyes of a young black southern African girl, offers some hope for the future. The girl, despite her refugee status, fully plans to return home where she believes her missing mother and grandfather are waiting.

Eventually, the desire to return home helps to bring a level of personal hope and political redemption to a narrative that is sadly lacking more of it.