"I don't see the word Botswana anywhere. I see someone who is ignorant writing ignorantly and someone excusing their ignorance based on an assumption."
It seems you are as ignorant of her language and culture as you accuse her of being of yours. No harm in that, I was too. But I had enough of a suspicion to drop "Motswana" into a search engine, and learned something kind of interesting about the way a particular language uses prefixes.
"There is no excuse for butchering the English language no matter what your ethnicity."
Someday you may learn that there are as many versions of the language as there are cultures which use it, especially those which use it to some degree alongside another.