"She is a second child"
Translation:Yeye ni mwana wa pili
Apparently, the male gender continues to be the default gender in Swahili, just as it was in English until recently when we began having to write him/her instead of him. Here, we know it's a girl they're telling about, but the statement places her in a general role - that of a second child. So for child, they use the default term mwana. They could as easily have written mtoto.
Good question! I thought that mwana meant 'son' (like in jina la baba, la mwana na roho takatifu, 'in the name of the father, the son and the holy spirit': a sentence that will be repeated ad inifitum in later lessons). The subject 'she' seems to rule that out, in this case :)