An important point is that this is not for us to decide. Development doesn't happen by us telling others how to develop, but by giving them the means to develop on their own. Maybe this person finds out that her choice was a mistake, but realistically, I believe that language studies is not the worst choice. There are many languages spoken in Tanzania (and any other african country) some of which are at risk of slowly dying out. Having a background in languages could make the difference in her ability to support her local language, not only to preserve it but to strengthen the confidence and self-image of its speakers which in itself can make a great impact in the development of that region. It could even be that it affects how much parents value their children going to school. We don't know any of this. Only the people living there can figure this out. All we can do is to provide some resources to help them along.